v. & n.
v. 1 a tr. strike (a hard surface) with an audible sharp blow (knocked the table three times). b intr. strike, esp. a door to gain admittance (can you hear someone knocking?; knocked at the door). 2 tr. make (a hole, a dent, etc.) by knocking (knock a hole in the fence). 3 tr. (usu. foll. by in, out, off, etc.) drive (a thing, a person, etc.) by striking (knocked the ball into the hole; knocked those ideas out of his head; knocked her hand away). 4 tr. sl. criticize. 5 intr. a (of a motor or other engine) make a thumping or rattling noise esp. as the result of a loose bearing. b = PINK(3). 6 tr. Brit. sl. make a strong impression on, astonish. 7 tr. Brit. coarse sl. offens. = knock off 7.
n. 1 an act of knocking. 2 a sharp rap, esp. at a door. 3 an audible sharp blow. 4 the sound of knocking in esp. a motor engine. 5 Cricket colloq. an innings. knock about (or around) 1 strike repeatedly; treat roughly (knocked her about). 2 lead a wandering adventurous life; wander aimlessly. 3 be present without design or volition (there's a cup knocking about somewhere). 4 (usu. foll. by with) be associated socially (knocks about with his brother). knock against 1 collide with. 2 come across casually. knock back 1 Brit. sl. eat or drink, esp. quickly. 2 Brit. sl. disconcert. 3 Austral. & NZ colloq. refuse, rebuff. knock-back n. Austral. & NZ colloq. a refusal, a rebuff. knock the bottom out of see BOTTOM. knock down 1 strike (esp. a person) to the ground with a blow. 2 demolish. 3 (usu. foll. by to) (at an auction) dispose of (an article) to a bidder by a knock with a hammer (knocked the Picasso down to him for a million). 4 colloq. lower the price of (an article). 5 take (machinery, furniture, etc.) to pieces for transportation. 6 US sl. steal. 7 Austral. & NZ sl. spend (a pay cheque etc.) freely. knock-down attrib.adj. 1 (of a blow, misfortune, argument, etc.) overwhelming. 2 Brit. (of a price) very low. 3 (of a price at auction) reserve. 4 (of furniture etc.) easily dismantled and reassembled.
n. Austral. & NZ sl. an introduction (to a person). knock for knock agreement an agreement between insurance companies by which each pays its own policyholder regardless of liability. knock one's head against come into collision with (unfavourable facts or conditions). knocking-shop Brit. sl. a brothel. knock into a cocked hat see COCK(1). knock into the middle of next week colloq. send (a person) flying, esp. with a blow. knock into shape see SHAPE. knock-kneed having knock knees. knock knees an abnormal condition with the legs curved inwards at the knee. knock off 1 strike off with a blow. 2 colloq. a finish work (knocked off at 5.30). b finish (work) (knocked off work early). 3 colloq. dispatch (business). 4 colloq. rapidly produce (a work of art, verses, etc.). 5 (often foll. by from) deduct (a sum) from a price, bill, etc. 6 sl. steal. 7 Brit. coarse sl. offens. have sexual intercourse with (a woman). 8 sl. kill. knock on Rugby Football drive (a ball) with the hand or arm towards the opponents' goal-line. knock-on n. an act of knocking on. knock-on effect a secondary, indirect, or cumulative effect. knock on the head 1 stun or kill (a person) by a blow on the head. 2 colloq. put an end to (a scheme etc.). knock on (or knock) wood US = touch wood. knock out 1 make (a person) unconscious by a blow on the head. 2 knock down (a boxer) for a count of 10, thereby winning the contest. 3 defeat, esp. in a knockout competition. 4 sl. astonish. 5 (refl.) colloq. exhaust (knocked themselves out swimming). 6 colloq. make or write (a plan etc.) hastily. 7 empty (a tobacco-pipe) by tapping. 8 Austral., NZ, & US sl. earn. knock sideways colloq. disconcert; astonish. knock spots off defeat easily. knock together put together or assemble hastily or roughly. knock under submit. knock up 1 make or arrange hastily. 2 drive upwards with a blow. 3 a become exhausted or ill. b exhaust or make ill. 4 Brit. arouse (a person) by a knock at the door. 5 Cricket score (runs) rapidly. 6 esp. US sl. make pregnant. 7 practise a ball game before formal play begins. knock-up n. a practice at tennis etc. take a (or the) knock be hard hit financially or emotionally.
[ ME f. OE cnocian: prob. imit. ]