\Im*par"i*syl*lab"ic\, 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.