Entry 1 sense Webster, 1913 Cyperaceous /(s?p`?r-?"sh?s [or] s?`p?r-)/ · Cyp·er·a·ceous · IPA 01 a. Of, pertaining to, or resembling, a large family of plants of which the sedge is the type. 1. Of, pertaining to, or resembling, a large family of plants of which the sedge is the type.(Bot.)