means Small portions of food eaten between regular meals, or the act of eating them.

from From 'snack,' which in Middle English (as 'snak') meant a snap or bite — borrowed from Middle Dutch 'snacken,' to snap or chatter, a cousin of the sound a dog's jaws make closing on something. For centuries a snack was literally a bite, a snatch of food taken in passing; only later did it settle into the cozy modern sense of treats between meals, with the plural 'snacks' carrying the cheerful implication that one was never going to be enough.