Green’s Dictionary of Slang

(Ulster) a small quantity, e.g. of food; thus brave lock, quare lock, a substantial amount.

1911		St J. Ervine Mixed Marriage Act I: A don’t like Hughie goin’ after Papishes. He knows a quare lock of them [...] Och, what wud a lock o’ weemen want t’be talkin’ about stracks fur.
1925		L. Mackay Mourne Folk 53: We have a ‘brave lock’ of cabbages in the garden.
1948		J. O’Connor Come Day – Go Day (1984) 11: ‘There you are,’ he cried. ‘Sixty-five in a loc of days and as supple’ – a plocker of coughing seized him.
1979		P. Tunney Stone Fiddle n.p.: There was a right lock of us sitting round so we made a ‘join’ and sent away to Carmichael’s for the poteen [BS].
1983		H. Glassie All Silver and No Brass 157: The word expanded to mean a small quantity of anything built up of similar units — ‘a lock of turf,’ ‘a lock of days’.