Source : Webster's Revised Unabridged Dictionary (1913)

Razorbill \Ra"zor*bill\, n. (Zo["o]l.)
   (a) A species of auk ({Alca torda}) common in the Arctic
       seas. See {Auk}, and Illust. in Appendix.
   (b) See {Cutwater}, 3.

Source : WordNet®

Alca torda
     n : black-and-white northern Atlantic auk having a compressed
         sharp-edged bill [syn: {razorbill}, {razor-billed auk}]