1. Any of various stout flightless marine birds of the family Spheniscidae, of cool regions of the Southern Hemisphere, having flipperlike wings and webbed feet adapted for swimming and diving, and short scalelike feathers that are white in front and black on the back.
2. Obsolete. The great auk.

[Possibly from Welsh pen gwyn, White Head (name of an island in Newfoundland), great auk : pen, chief, head + gwynn, white.]

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.