PETROLOGIST
Pe*trol"o*gist, n.
Defn: One who is versed in petrology.
PETROLOGY
Pe*trol"o*gy, n. Etym: [Petro + -logy.]
1. The department of science which is concerned with the mineralogical and chemical composition of rocks, and with their classification: lithology.
2. A treatise on petrology.
PETROMASTOID
Pet`ro*mas"toid, a. Etym: [Petro + mastoid.] (Anat.)
Defn: Of or pertaining to the petrous and mastoid parts of the temporal bone, periotic.
PETROMYZONT
Pet`ro*my"zont, n. Etym: [Petro + Gr. (Zoöl.)
Defn: A lamprey.
PETRONEL Pet`ro*nel, n. Etym: [OF. petrinal, fr. peitrine, petrine, the breast, F. poitrine; so called because it was placed against the breast in order to fire. See Poitrel.]