noggin

The story

Uncertain. First use appears c. 1588. Appears in publications in the 1600s (e.g. in The Tincker of Turvey) in several forms including the still-current Irish English form naggin, the rare older Irish, Scottish and Northern English form noggan, used by Jonathan Swift, and the Wexford form nuggeen. Tomás S. Ó Máille and some older dictionaries like Skeat's derive it from Irish naigín, cnaigín, from cnagaire, cnag, but the Oxford English Dictionary argues that Irish naigín and Scottish Gaelic noigean instead derive from English. Compare nog.