Snack \Snack\, n. [See Snatch, v. t.]

1. A share; a part or portion; -- obsolete, except in the colloquial phrase, to go snacks, i. e., to share.

At last he whispers, ``Do, and we go snacks.'' --Pope.

2. A slight, hasty repast. [Colloq.]

Source: Webster's Revised Unabridged Dictionary (1913)