Translation according to P. W. Joyce:
Booley, Bola, Boola, Bool, the most usual anglicised forms of buaile, a milking or dairy-place, for which see vol. i. p. 239. Latterly the term was often applied to any cattle enclosure near the homestead where cows were brought together morning and evening and fed and milked. Boolies, the same only with the English plural: p. 11 [reproduced below].
Many of our local names - for obvious reasons - are plural, as happens in all other countries (vol. i. p.32). Very often in such cases, the Irish plural termination is rejected in anglicisation and the English plural termination s adopted.