\Tri`dec*a*to"ic\ (tr[-i]`d[e^]k*[.a]*t[=o]"[i^]k), a. [Pref. tri- + Gr. de`katos tenth.] (Chem.) Of, pertaining to, or designating, that acid of the fatty acids heterologous with tridecane. It is a white crystalline substance.