PROTOSULPHIDE
Pro`to*sul"phide, n. Etym: [Proto- + sulphide.] (Chem.)
Defn: That one of a series of sulphides of any element which has the lowest proportion of sulphur; a sulphide with but one atom of sulphur in the molecule.
PROTOSULPHURET
Pro`to*sul"phu*ret, n. Etym: [Proto- + sulphuret.] (Chem.)
Defn: A protosulphide. [Obs.]
PROTOTHERIA
Pro`to*the"ri*a n. pl. Etym: [NL., from Gr. (Zoöl.)
Defn: Same as Monotremata.
PROTOTRACHEATA
Pro`to*tra`che*a"ta, n. pl. Etym: [NL. See Proto-, and Trachea.]
(Zoöl.)
Defn: Same as Malacopoda.
PROTOTYPE
Pro"to*type, n. Etym: [F., from L. prototypus original, primitive,
Gr. Proto-, and Type]
Defn: An original or model after which anything is copied; the pattern of anything to be engraved, or otherwise copied, cast, or the like; a primary form; exemplar; archetype. They will turn their backs on it, like their great precursor and prototype. Burke.