a. [ L. impar unequal + E. syllabic: cf. F. imparisyllabique. ] (Gram.) Not consisting of an equal number of syllables; as, an imparisyllabic noun, one which has not the same number of syllables in all the cases; as, lapis, lapidis; mens, mentis. [ 1913 Webster ]

{ } a. [ Pari- + syllabic, -ical: cf. F. parisyllabique. ] Having the same number of syllables in all its inflections. [ 1913 Webster ]