<B>echidna, </B>noun, pl. <B>-nas,</B> <B>-nae.</B><DL COMPACT><DD> a small, egg-laying, ant-eating mammal of Australia, Tasmania, and New Guinea, with a long, slender snout, no teeth, and a covering of spines; spiny anteater; porcupine anteater. </DL>
<A NAME="echidna">
<B>Echidna, </B>noun.<DL COMPACT><DD> (Greek Mythology.) a female monster, mother of Cerberus, the Chimera, and the Sphinx. </DL>
<A NAME="echinate">
<B>echinate, </B>adjective.<DL COMPACT><DD> covered with spines; spiny; bristly. </DL>
<B>echini, </B>noun.<DL COMPACT><DD> plural of <B>echinus.</B> </DL>
<A NAME="echinite">
<B>echinite, </B>noun.<DL COMPACT><DD> a fossil sea urchin. </DL>
<A NAME="echinococcosis">
<B>echinococcosis, </B>noun.<DL COMPACT><DD> a disease caused by the infestation of tissues and organs with the larvae of hydatid tapeworms. </DL>
<A NAME="echinoderm">
<B>echinoderm, </B>noun.<DL COMPACT><DD> any one of a group of small sea animals including starfish and sea urchins. An echinoderm has a spiny, stony shell and a body whose parts are arranged like the spokes of a wheel. </DL>
<B>Echinodermata, </B>noun pl.<DL COMPACT><DD> the phylum of invertebrates comprising the echinoderms. </DL>
<A NAME="echinodermatous">
<B>echinodermatous, </B>adjective.<DL COMPACT><DD><B> 1. </B>having a skin consisting of small, slender, bony, sharp-pointed pieces. <DD><B> 2. </B>of or having to do with the echinoderms. </DL>
<A NAME="echinoid">
<B>echinoid, </B>adjective, noun.<DL COMPACT><DD><I>adj. </I> <B>1. </B>like a sea urchin. <DD><B> 2. </B>belonging to the class of sea urchins. <DD><I>noun </I> <B>=sea urchin.</B> </DL>
<A NAME="echinulate">
<B>echinulate, </B>adjective.<DL COMPACT><DD> having or covered with small prickles; echinate. <BR> <I>Ex. echinulate spores.</I> adv. <B>echinulately.</B> </DL>
<A NAME="echinus">
<B>echinus, </B>noun, pl. <B>-ni.</B><DL COMPACT><DD><B> 1. </B><B>=sea urchin.</B> <DD><B> 2. </B>a rounded molding at the top of a Doric column. </DL>
<A NAME="echium">
<B>echium, </B>noun.<DL COMPACT><DD> any plant of a group of herbs or shrubs of the borage family, cultivated for their showy, white, blue, or purple flowers; blueweed. </DL>
<B>echiuroid, </B>adjective, noun.<DL COMPACT><DD><I>adj. </I> of or belonging to a group of marine worms related to the sipunculids. <DD><I>noun </I> an echiuroid worm. </DL>
<A NAME="echo">
<B>echo, </B>noun, pl. <B>echoes,</B> verb, <B>echoed,</B> <B>echoing.</B><DL COMPACT><DD><I>noun </I> <B>1. </B>a sounding again; a repeating of a sound; sound heard after it is reflected from some object. You hear an echo if you shout and the sound is sent back by a cliff or hill or the walls of a large, empty room and heard again as it from a distance. <BR> <I>Ex. Blow, bugle, blow, set the wild echoes flying, And answer echoes, answer, dying, dying, dying (Tennyson).</I> (SYN) reverberation. <DD><B> 2. </B>(Figurative.) a person who repeats the words or imitates the feelings, acts, ideas, or style of another. <BR> <I>Ex. Better be a nettle in the side of your friend than his echo (Emerson).</I> <DD><B> 3. </B>(Figurative.) a repeating the words or imitating the feelings, acts, ideas, or style of another. <BR> <I>Ex. His folly and his wisdom ... are all of his own growth, not the echo ... of other men (Jonathan Swift).</I> <DD><B> 4. </B>(Figurative.) a sympathetic response. <BR> <I>Ex. Patriotic sentiments evoke an echo in every breast.</I> <DD><B> 5. </B>a radio or sound wave which has been reflected. The detection of radio or sound wave reflections is the basis of radar and sonar. <BR> <I>Ex. ... the familiar processes of radar to explore space around us by sending out powerful signals and looking carefully at the echoes when they come back (A. J. Higgs).</I> <DD><B> 6. </B>(Music.) <DD><B> a. </B>a very soft repetition of a phrase. <DD><B> b. </B>a stop of an organ for producing soft or echolike tones. <DD><B> 7. </B>a cardplayer's response to a signal from his partner or by a signal to his partner's lead. <DD><I>v.i. </I> <B>1. </B>to be heard again; sound again; be repeated in sound. <BR> <I>Ex. The gunshot echoed through the valley. Larks and nightingales make the sky echo with sound (William Butler Yeats).</I> <DD><B> 2. </B>(Figurative.) to repeat or imitate the words, feelings, acts, ideas, or style of another. <BR> <I>Ex. I would repeat a stanza and he would softly echo.</I> <DD><B> 3. </B>to give out a loud sound. <BR> <I>Ex. Drums and trumpets echo loudly (Longfellow).</I> <DD><I>v.t. </I> <B>1. </B>to sound again; repeat in sound. <BR> <I>Ex. The mountains echoed the yodeler's call.</I> <DD><B> 2. </B>(Figurative.) to say or do always what another says or does. <BR> <I>Ex. That girl is always echoing what her mother says.</I> noun <B>echoer.</B> </DL>
<A NAME="echo">
<B>Echo, </B>noun.<DL COMPACT><DD><B> 1. </B>(Greek Legend.) a nymph who pined away with love for Narcissus until only her voice was left. <DD><B> 2. </B>echo personified. <DD><B> 3. </B>(U.S.) a code name for the letter <I>e,</I> used in transmitting radio messages. </DL>
<A NAME="echocardiography">
<B>echocardiography, </B>noun.<DL COMPACT><DD> the use of ultrasonic apparatus for diagnosing cardiac tumors and diseased valves by analyzing the sound waves reflected from parts of the heart. <BR> <I>Ex. The principle underlying the technique is the graphic recording of high frequency sound waves as they bounce back to the recorder after striking an unusual structure within or outside the heart. This technique is also known as echocardiography (Johnson McGuire and Arnold Iglauer).</I> </DL>
<A NAME="echochamber">
<B>echo chamber,</B><DL COMPACT><DD> a room designed to create echoes and other sound effects, especially for radio and phonograph records. </DL>
<A NAME="echoencephalography">
<B>echoencephalography, </B>noun.<DL COMPACT><DD> the use of ultrasonic apparatus for diagnosing cerebral tumors and lesions by analyzing the sound waves reflected from parts of the brain. <BR> <I>Ex. Echoencephalography got its start in 1954 when Lars Leksell, a Swedish neurosurgeon, reported the use of pulsed ultrasound to reveal lateral shifts in certain structures which normally lie in the medial plane of the brain (Science News).</I> </DL>
<A NAME="echoey">
<B>echoey, </B>adjective.<DL COMPACT><DD> of or like an echo; echoic. <BR> <I>Ex. The Brazilian pianist ... leads ... into a mad, echoey jumble such as that heard during the Schumann Toccata (New York Times).</I> <DD><B> 1. </B>given to echoing. <BR> <I>Ex. It's very echoey, symmetrical, and penal looking (Listener).</I> </DL>
<A NAME="echogram">
<B>echogram, </B>noun.<DL COMPACT><DD> a chart or diagram drawn by an echograph. <BR> <I>Ex. Our echograms, drawn by an ultrasonic depth recorder, had delineated with unprecedented detail the profile of the bottom for 17,000 miles of our course (Scientific American).</I> </DL>
<A NAME="echograph">
<B>echograph, </B>noun.<DL COMPACT><DD> a machine that emits sound waves and records them when they echo back after hitting an object. It is used to detect fish, chart ocean floors, and the like. </DL>
<A NAME="echoic">
<B>echoic, </B>adjective.<DL COMPACT><DD><B> 1. </B>like an echo. <DD><B> 2. </B>imitating a sound; onomatopoetic. <BR> <I>Ex. "Buzz," "caw," and "moo" are echoic words.</I> </DL>
<A NAME="echoingly">
<B>echoingly, </B>adverb.<DL COMPACT><DD> so as to echo or reverberate sounds. </DL>
<A NAME="echoism">
<B>echoism, </B>noun. <B>=onomatopoeia.</B></DL>
<A NAME="echolalia">
<B>echolalia, </B>noun.<DL COMPACT><DD> (Psychology.) the meaningless repetition of words. It is common in the speech of very young children and sometimes associated with mental disorder. </DL>
<B>echolocate, </B>transitive verb, <B>-cated,</B> <B>-cating.</B><DL COMPACT><DD> to locate distance and direction by means of echoes. </DL>
<A NAME="echolocation">
<B>echolocation, </B>noun.<DL COMPACT><DD><B> 1. </B>(Electronics.) a method of finding the range and direction of objects by measuring the time it takes sound or radio waves echoed from the objects to reflect back, used in radar and sonar. <DD><B> 2. </B>a radarlike system or mechanism of orientation in the sensory organs of certain mammals, such as bats or whales, by which they translate their own echoes into directional signals that permit them to avoid all obstacles in their path. <BR> <I>Ex. However, another theory about moth behaviour, in which sound acts as an aid to navigation, suggests that they use a system of echolocation analogous with that of bats (P. T. Haskell).</I> </DL>
<A NAME="echoorgan">
<B>echo organ,</B><DL COMPACT><DD> a set of pipes in an organ, enclosed in a wooden box to give a distant sound effect. </DL>
<A NAME="echopraxia">
<B>echopraxia, </B>noun.<DL COMPACT><DD> (Psychology.) the compulsive repetition of the actions of other people. </DL>
<A NAME="echoranging">
<B>echo ranging,</B><DL COMPACT><DD> a method of finding the range and direction of objects submerged under water by transmitting sound under water at supersonic frequencies, timing its speed, and measuring the direction of its echo. </DL>
<A NAME="echosounder">
<B>echo sounder,</B><DL COMPACT><DD> an instrument that determines the depth of a body of water (notably the ocean's depth) by measuring the time it takes sound waves echoed from the water floor to reach the surface. </DL>
<A NAME="echosounding">
<B>echo sounding,</B><DL COMPACT><DD> the technique of measuring the depth of a body of water by means of an echo sounder. <BR> <I>Ex. Echo sounding involves the use of sound waves emitted underwater from the hull of a vessel which travel to the bottom of the ocean and are reflected back (Science News Letter).</I> </DL>
<A NAME="echovirus">
<B>echovirus, </B>noun, or <B>ECHO virus,</B><DL COMPACT><DD> a type of virus associated with various kinds of meningitis, intestinal diseases, and respiratory illnesses in human beings. <BR> <I>Ex. Polioviruses, reoviruses, echoviruses and infectious hepatitis virus still circulate widely (New Scientist).</I> </DL>
<A NAME="echt">
<B>echt, </B>adjective, adverb.<DL COMPACT><DD> (German.) genuine. <BR> <I>Ex. To the echt Harvard man of yore, a gentleman should schedule no course before 11:00 A.M. or in a classroom above the second floor (Harper's).</I> </DL>
