From Rural Irish to the Queen's English

The Oxford English Dictionary gives an ‘etymology unknown’ for quaff, a first recording in 1579, and a meaning of ‘a deep draught’ and ‘amount of liquid’. No Irish connection as suggested by Sandi Tocsvig is apparent, but if we go to Niall O Dónaill’s Foclóir Gaeilge Béarla there is the word cuaifeach for ‘whirling’ or ‘swirling’ (the word being pronounced something like ‘quaffack’) and cuaifeach uisce as the word for a ‘water spout’.