Thick″en (?), v. t. [imp. & p. p.Thickened (?); p. pr. & vb. n.Thickening.] To make thick (in any sense of the word). Specifically: —
(a) To render dense; to inspissate; as, to thicken paint.
(b) To make close; to fill up interstices in; as, to thicken cloth; to thicken ranks of trees or men.
(c) To strengthen; to confirm.
And this may to thicken other proofs. Shak.
(d) To make more frequent; as, to thicken blows.