(1):
(v. t.) To strengthen; to confirm.
(2):
(v. t.) To make more frequent; as, to thicken blows.
(3):
(v. t.) To make thick (in any sense of the word).
(4):
(v. t.) To render dense; to inspissate; as, to thicken paint.
(5):
(v. t.) To make close; to fill up interstices in; as, to thicken cloth; to thicken ranks of trees or men.
(6):
(v. i.) To become thick.