<B>photopolarimeter, </B>noun.<DL COMPACT><DD> an instrument combining telescopic, photographic, and polarimetric apparatus for producing detailed images of planetary features. </DL>
<A NAME="photopolymer">
<B>photopolymer, </B>noun.<DL COMPACT><DD> a plastic made by photopolymerization, used especially to make printing plates. </DL>
<A NAME="photopolymerization">
<B>photopolymerization, </B>noun.<DL COMPACT><DD> polymerization induced by the action of light. </DL>
<A NAME="photopositive">
<B>photopositive, </B>adjective.<DL COMPACT><DD> attracted to light; photophilous; phototactic. </DL>
<A NAME="photoprint">
<B>photoprint, </B>noun.<DL COMPACT><DD> a print produced by a photomechanical process. </DL>
<A NAME="photoreaction">
<B>photoreaction, </B>noun.<DL COMPACT><DD> any chemical reaction induced by the presence of light. </DL>
<A NAME="photorealism">
<B>Photo-Realism, </B>noun.<DL COMPACT><DD> a form of painting based on and often imitating still photographs. <BR> <I>Ex. Photo-Realism is photographic (many of the Photo-Realist painters simply copy blown-up photographs they have projected onto their enormous canvases) and cruelly noticing of things as they are (New Yorker).</I> adj., n. <B>Photo-Realist.</B> </DL>
<B>photoreception, </B>noun.<DL COMPACT><DD> the reception of and response to light by plant or animal cells having pigments sensitive to radiant energy. Photoreception is essential to photosynthesis and phototropism in plants, and to vision in animals. <BR> <I>Ex. The collective evidence in favor of photoreception by some form of riboflavin conjugate is also sufficiently impressive (Scientific American).</I> </DL>
<A NAME="photoreceptive">
<B>photoreceptive, </B>adjective.<DL COMPACT><DD> of or having to do with photoreception. </DL>
<A NAME="photoreceptor">
<B>photoreceptor, </B>noun.<DL COMPACT><DD> a nerve ending which is sensitive to light. <BR> <I>Ex. Rod photoreceptors of the eye are responsible for colourless vision of low intensities (New Scientist).</I> </DL>
<A NAME="photoreconnaissance">
<B>photoreconnaissance, </B>noun.<DL COMPACT><DD> aerial reconnaissance during which information is gathered by taking aerial photographs. <BR> <I>Ex. Photoreconnaissance indicated that the enemy had ... a larger type of rocket (James Phinney Baxter).</I> </DL>
<A NAME="photoresist">
<B>photoresist, </B>noun.<DL COMPACT><DD> a plastic material that hardens to varying degrees depending on the intensity of the light to which it is exposed, used especially as a protective coating on the surface of silicon wafers or chips. </DL>
<A NAME="photorespiration">
<B>photorespiration, </B>noun.<DL COMPACT><DD> (Botany.) respiration induced or stimulated by the presence of light. </DL>
<A NAME="photoscanner">
<B>photoscanner, </B>noun.<DL COMPACT><DD> a device that reproduces on X-ray film the distribution of a radioactive isotope injected in the body for diagnostic purposes. <BR> <I>Ex. The gamma rays coming from the abnormal portions of bone are detected by a photoscanner that is passed externally over the body (Science News).</I> </DL>
<A NAME="photoscanning">
<B>photoscanning, </B>noun.<DL COMPACT><DD> the use of a photoscanner. </DL>
<A NAME="photosensitive">
<B>photosensitive, </B>adjective.<DL COMPACT><DD> readily stimulated to action by light or other radiant energy. </DL>
<A NAME="photosensitiveglass">
<B>photosensitive glass,</B><DL COMPACT><DD> a special glass which, upon exposure to a photographic negative, develops a print when heated. It is used for making ornaments, permanent records, etc. </DL>
<A NAME="photosensitivity">
<B>photosensitivity, </B>noun.<DL COMPACT><DD> the quality of being readily stimulated to action by light or other radiant energy. </DL>
<A NAME="photosensitization">
<B>photosensitization, </B>noun.<DL COMPACT><DD> the act or process of photosensitizing. </DL>
<A NAME="photosensitize">
<B>photosensitize, </B>transitive verb, <B>-tized,</B> <B>-tizing.</B><DL COMPACT><DD> to make sensitive to the action of light; make photosensitive. </DL>
<A NAME="photosensor">
<B>photosensor, </B>noun.<DL COMPACT><DD> a device that is sensitive to light. <BR> <I>Ex. In a study of commonly used type fonts, for instance, it has been found that 24 rows of photosensors are necessary to recognise unambiguously a typical character (New Scientist).</I> </DL>
<B>photospectroscope, </B>noun.<DL COMPACT><DD> a spectroscope with an attached camera, used for photographing and recording spectra. </DL>
<A NAME="photospectroscopic">
<B>photospectroscopic, </B>adjective.<DL COMPACT><DD> having to do with photographing and recording spectra with a spectroscope. </DL>
<A NAME="photosphere">
<B>photosphere, </B>noun.<DL COMPACT><DD><B> 1. </B>the brilliant gaseous layer surrounding the sun or other stars. <BR> <I>Ex. While the particles in the corona move at a far higher speed than those in the photosphere, they are so much more thinly dispersed that radiating collisions are relatively infrequent (Fred Hoyle).</I> <DD><B> 2. </B>(Figurative.) a sphere of light, radiance, or glory. <BR> <I>Ex. Her hopes mingled with the sunshine in an ideal photosphere (Thomas Hardy).</I> </DL>
<A NAME="photospheric">
<B>photospheric, </B>adjective.<DL COMPACT><DD><B> 1. </B>of or having to do with the photosphere or a photosphere. <DD><B> 2. </B>characteristic of the photosphere or a photosphere. </DL>
<A NAME="photostat">
<B>photostat, </B>noun, verb, <B>-stated,</B> <B>-stating</B> or <B>-statted,</B> <B>-statting.</B><DL COMPACT><DD><I>noun </I> <B>1. </B>a photograph made with a special camera for making photocopies of documents, maps, drawings, pages of books, and other printed material, directly on specially prepared paper. <DD><B> 2. </B><B>Photostat,</B> (Trademark.) a name for a camera of this kind. <DD><I>v.t. </I> to make a photostat of. noun <B>photostater.</B> </DL>
<A NAME="photostatic">
<B>photostatic, </B>adjective.<DL COMPACT><DD><B> 1. </B>of or having to do with a photostat. <DD><B> 2. </B>produced by a photostat. </DL>
<A NAME="photosurface">
<B>photosurface, </B>noun.<DL COMPACT><DD> a photographic surface. <BR> <I>Ex. Every time an exposed photographic plate is removed, the air destroys the highly reactive photosurface (Scientific American).</I> </DL>
<A NAME="photosynthesis">
<B>photosynthesis, </B>noun.<DL COMPACT><DD><B> 1. </B>the process by which plant cells make carbohydrates from carbon dioxide and water in the presence of chlorophyll and light, and release oxygen as a by-product. <BR> <I>Ex. Photosynthesis, called by some the most important chemical reaction occurring in nature, takes place only in plants containing certain pigments, principally chlorophyll (Harbaugh and Goodrich).</I> <DD><B> 2. </B>the process by which chemical compounds are synthesized by means of light or other forms of radiant energy. </DL>
<A NAME="photosynthesize">
<B>photosynthesize, </B>verb, <B>-sized,</B> <B>-sizing.</B><DL COMPACT><DD><I>v.i. </I> to carry on photosynethesis. <BR> <I>Ex. A red alga is best adapted to photosynthesize in the bluish-green light of deep water (G. E. Fogg).</I> <DD><I>v.t. </I> to produce by photosynethesis. <BR> <I>Ex. Plants photosynthesize protein as well as carbohydrates directly under light (Time).</I> </DL>
<A NAME="photosynthetic">
<B>photosynthetic, </B>adjective.<DL COMPACT><DD><B> 1. </B>of or having to do with photosynthesis. <BR> <I>Ex. The crux of the whole photosynthetic process was the conversion of light energy into chemical energy (Harper's).</I> <DD><B> 2. </B>promoting photosynthesis. <BR> <I>Ex. The photosynthetic function is accomplished by the green stems (Fred W. Emerson).</I> adv. <B>photosynthetically.</B> </DL>
<A NAME="phototactic">
<B>phototactic, </B>adjective.<DL COMPACT><DD> of, having to do with, or characterized by phototaxis. <BR> <I>Ex. A phototropic or phototactic response might become dependent on the oxygen supplied by photosynthesis (Scientific American).</I> </DL>
<A NAME="phototaxis">
<B>phototaxis, </B>noun.<DL COMPACT><DD> the tendency of an organism to move in response to light. <BR> <I>Ex. Several workers have found negative phototaxis (movement away from light) in a number of species (E. B. Edney).</I> </DL>
<A NAME="phototaxy">
<B>phototaxy, </B>noun. <B>=phototaxis.</B></DL>
<A NAME="phototelegraph">
<B>phototelegraph, </B>verb, noun.<DL COMPACT><DD><I>v.t., v.i. </I> to send by phototelegraphy. <DD><I>noun </I> a picture, message, or other printed matter, thus sent. </DL>
<A NAME="phototelegraphic">
<B>phototelegraphic, </B>adjective.<DL COMPACT><DD> of or having to do with phototelegraphy. adv. <B>phototelegraphically.</B> </DL>
<B>phototelegraphy, </B>noun.<DL COMPACT><DD><B> 1. </B>telegraphy by means of light, as with a heliograph. <DD><B> 2. </B>the electric transmission of facsimiles of photographs; telephotography. </DL>
<A NAME="phototelescope">
<B>phototelescope, </B>noun.<DL COMPACT><DD> a telescope with a photographic apparatus, used for photographing heavenly bodies. </DL>
<A NAME="phototelescopic">
<B>phototelescopic, </B>adjective.<DL COMPACT><DD> of or having to do with a phototelescope. </DL>
<A NAME="phototheodolite">
<B>phototheodolite, </B>noun.<DL COMPACT><DD> a camera with the movability of a theodolite, used for tracking space vehicles or for photographing very large objects. </DL>
<A NAME="phototherapeutic">
<B>phototherapeutic, </B>adjective.<DL COMPACT><DD> having to do with phototherapy. </DL>
<B>phototherapy, </B>noun.<DL COMPACT><DD><B> 1. </B>therapy in which light rays are used, as in treating certain skin diseases. <DD><B> 2. </B>the use of photographic images to diagnose mental problems and help patients to cope with them. <BR> <I>Ex. Phototherapy is based on the knowledge that visual images can accurately convey messages about how a person thinks and feels--messages that could be overlooked in verbal communication (Brian Zakem).</I> </DL>
<A NAME="photothermic">
<B>photothermic, </B>adjective.<DL COMPACT><DD><B> 1. </B>having to do with the heating effects of light. <DD><B> 2. </B>of or relating to both light and heat. </DL>
