Green’s Dictionary of Slang

to nag, to criticize.

1873		Sl. Dict. 298: Snack to quiz or chaff with regard to a particular weakness or recent transaction.
1882		Daily Tel. 6 Oct. 2: Now, I’ve got to come home boozed, don’t you know, and you are sitting up for me, and you begin to snack me about it, and then there’s a jolly row.