Knock (nŏk), v. i. [imp. & p. p.Knocked (nŏkt); p. pr. & vb. n.Knocking.] [OE. knoken, AS. cnocian, cnucian; prob. of imitative origin; cf. Sw. knacka. Cf. Knack.] 1. To drive or be driven against something; to strike against something; to clash; as, one heavy body knocks against another. Bacon.
2. To strike or beat with something hard or heavy; to rap; as, to knock with a club; to knock on the door.
For harbor at a thousand doors they knocked. Dryden.
Seek, and ye shall find; knock, and it shall be opened unto you. Matt. vii. 7.
To knock about, to go about, taking knocks or rough usage; to wander about; to saunter. “Knocking about town.” W. Irving. — To knock up, to fail of strength; to become wearied or worn out, as with labor; to give out. “The horses were beginning to knock up under the fatigue of such severe service.” De Quincey. — To knock off, to cease, as from work; to desist. — To knock under, to yield; to submit; to acknowledge one's self conquered; — an expression probably borrowed from the practice of knocking under the table with the knuckles, when conquered. “Colonel Esmond knocked under to his fate.” Thackeray.