What does "guillemot" mean?

Guillemot: One of several northern sea birds, allied to the auks. They have short legs, placed far back, and are expert divers and swimmers. Note: The common guillemots, or murres, belong to the genus Uria (as U. troile); the black or foolish guillemot (Cepphus grylle, formerly Uria grylle), is called also sea pigeon and eligny. See Murre.