1.genus Cepphus - a genus of birds including: guillemotsCepphusbird genus - a genus of birdsAlcidae, family Alcidae - web-footed diving seabirds of northern seas: auks; puffins; guillemots; murres; etc.guillemot - small black or brown speckled auks of northern seas
genus Cepphus - a genus of birds including: guillemots