Paragnathus \Pa*rag"na*thus\ (p[.a]*r[a^]g"n[.a]*th[u^]s), n.; pl. {Paragnathi} (p[.a]*r[a^]g"n[.a]*th[imac]). [NL. See {Para-}, and {Gnathic}.] (Zool.) (a) One of the two lobes which form the lower lip, or metastome, of Crustacea. (b) One of the small, horny, toothlike jaws of certain annelids. [1913 Webster]