Толковый словарь английского языка Oxford English Reference - navelwort n. a pennywort.

navicular adj. & n. --adj. boat-shaped. --n. (in full navicular bone) a boat-shaped bone in the foot or hand. Phrases and idioms navicular disease an inflammatory disease of the navicular bone in horses, causing lameness. Etymology: F naviculaire or LL navicularis f. L navicula dimin. of navis ship