1578, originally used of the great auk of Newfoundland (now extinct), shift in meaning to the Antarctic bird (which looks something like it, found by Drake in Magellan's Straits in 1578) is from 1588. Of unknown origin, though often asserted to be from Welsh pen
"head" + gwyn
"white" (see Gwendolyn
). The great auk had a large white patch between its bill and eye. The Fr. and Breton versions of the word are ult. from English. The book publishing company of this name is from 1935.