similar in shape and habitat but has a black-and-white beak without orange or yellow
Synonym discussion
Sense: noun/1
All four words refer to seabirds in the family Alcidae that nest on northern sea cliffs. 'Puffin' is the only one with a large, brightly coloured beak (orange, yellow, and blue) and a plump body. 'Auk' is a broader term for several similar birds with plain, dark beaks. 'Guillemot' describes a slimmer bird with a thin black bill and brown-black feathers. 'Razorbill' has a black-and-white body like a puffin but its beak is black with a white line, not colourful. For example, a visitor to an Icelandic cliff might say 'Look at the puffin with its rainbow beak' but would say 'That razorbill has a plain black beak with a white stripe.'
The English word 'puffin' first appeared around the 1300s, possibly from the Middle English word 'pophyn' or from 'puff' — a reference to the round, plump shape of the bird's body. The name was originally used for the cured carcass of a Manx shearwater chick, which looked puffy. By the 1600s, it had become the common name for the colourful-beaked Atlantic bird we know today.