rugose UK /ɹʊˈɡəʊs/US /ˌɹuːˈɡoʊs/ adjective5 •Having rugae or wrinkles, creases, ridges, or corrugation. •Having a rough, wrinkled, or wavy surface; commonly in parasynthetic usage e.g. "rugose-veined" or "rugose-leaved".The original leaves were flat and very rugose, and almost hid by the numerous single-stemmed flowers; while the leaves produced in the umbellate state were larger, more upright, and less wrinkled. — 1866 •Used when combined with another adjective, for example, rugose-reticulate or rugose-punctate. •Describing fossil corals of the extinct order †Rugosa (also called Tetracoralla), that have horn-shaped corals with surfaces covered with ridges. •(figurative, rare) Rugged, rough, unrefined. formsmore rugose · most rugose