Cheek, n.

n. [A-S. ceac, m., or ceace, f., D. kaak, O. H. Ger. kouwe, jaw, from A-S. ceowan, to chew, O. H. Ger. kiuwan, N. H. Ger. kauen, D. kaauwen. Cf. CHAW, v. t.] 1. The side of the face below the eyes on either side.

2. (pl.) (Mech.) Those pieces of a machine which form corresponding sides, or which are similar and in pairs; as, the cheeks of a printing-press; the cheeks of a turner's lathe; the cheeks of a vise, &c.
3. (pl.) (Founding.) The middle part of a flask, when it is composed of more than two parts.

Cheek by jowl, in familiar proximity; close.