Placoderm, plak′o-dėrm, adj. noting an order of fossil fishes having their skin covered with bony plates. [Gr. plax, plakos, anything flat, derma, skin.]
Placoid, plak′oid, adj. plate-like.—Placoid fishes, an order of fishes having placoid scales, irregular plates of hard bone, not imbricated, but placed near together in the skin. [Gr. plax, plakos, anything flat and broad, eidos, form.]
Placula, plak′ū-la, n. a little plate or plaque.—adjs. Plac′ular, Plac′ulāte.
Plafond, pla-fond′, n. the ceiling of a room, any soffit. [Fr.]
Plagal, plā′gal, adj. in Gregorian music, denoting a mode or melody in which the final is in the middle of the compass instead of at the bottom—opp. to Authentic. [Gr. plagios, sidewise—plagos, a side.]
Plagiarise, plā′ji-ar-īz, v.t. to steal from the writings or ideas of another.—ns. Plā′giarism, the act or practice of plagiarising; Plā′giarist, one who plagiarises; Plā′giary, one who steals the thoughts or writings of others and gives them out as his own: the crime of plagiarism.—adj. practising literary theft. [Fr. plagiaire—L. plagiarius, a kidnapper—plaga, a net.]
Plagioclase, plā′ji-ō-klāz, n. a group of triclinic feldspars whose cleavage planes are not at right angles to each other.—adj. Plagioclas′tic. [Gr. plagios, oblique, klasis, a fracture.]
Plagiodont, plā′ji-ō-dont, adj. having the teeth oblique.
Plagiostome, plā′ji-ō-stōm, n. a plagiostomous fish, one of the Plagios′tomi, a division of fishes, including sharks and rays.—adjs. Plagiostom′atous, Plagios′tomous.
Plagiotropism, plā-ji-ot′rō-pizm, n. a mode of turning of the organs of plants in the direction of gravitation or of the ray of light.—adj. Plagiotrop′ic.—adv. Plagiotrop′ically. [Gr. plagios, oblique, tropos, a turning.]