From Wiktionary, the free dictionary
Borrowed from Irish pocán.
puckaun (plural puckauns)
- (Ireland) A he-goat.
1953, Samuel Beckett, Watt, 1st American edition, New York, N.Y.: Grove Press, published 1959, →OCLC:Riley's puckaun again, said Mr. Nolan, I can smell him from here.