Lock

n.

Heard in Roscommon, Offaly, Galway, Monaghan, Donegal and Tyrone

A quantity or amount of something.

In use

Bring in a lock o' spuds for the dinner." "Throw in a lock o' nuts to the cattle.

Posh English

Pray fetch a fair quantity of tubers for the evening meal. Throw in a fair quantity of nuts for the cattle.

Same phrase, other counties