- hazelnut, filbert, cobnut, cob - nut of any of several trees of the genus Corylus
--1 is a kind of edible nut
--1 is a part of hazelnut, hazel, hazelnut tree - cob - stocky short-legged harness horse
--2 is a kind of harness horse
- black-backed gull, great black-backed gull, cob, Larus marinus - white gull having a black back and wings
--3 is a kind of gull, seagull, sea gull
--3 is a member of Larus, genus Larus- cob - adult male swan
--4 is a kind of swan
- black-backed gull, great black-backed gull, cob, Larus marinus - white gull having a black back and wings