Noun | 1. | ![]() seal - any of numerous marine mammals that come on shore to breed; chiefly of cold regions family Phocidae, Phocidae - earless seals common seal, harbor seal, Phoca vitulina - small spotted seal of coastal waters of the northern hemisphere harp seal, Pagophilus groenlandicus - common Arctic seal; the young are all white elephant seal, sea elephant - either of two large northern Atlantic earless seals having snouts like trunks bearded seal, Erignathus barbatus, squareflipper square flipper - medium-sized greyish to yellow seal with bristles each side of muzzle; of the Arctic Ocean bladdernose, Cystophora cristata, hooded seal - medium-sized blackish-grey seal with large inflatable sac on the head; of Arctic and northern Atlantic waters |