Definition of puffin:
(n) :
The Atlantic puffin (Fratercula arctica) or (by extension) any of the other various small seabirds of the genera Fratercula and Lunda that are black and white with a brightly-coloured beak.
(n) :
(entomology) Any of various African and Asian pierid butterflies of the genus Appias. Some species of this genus are also known as albatrosses.
(n) :
(now obsolete) The young of the Manx shearwater (Puffinus puffinus), especially eaten as food.
(n) :
(obsolete) A puffball.