The Collaborative International Dictionary
Knock down \Knock" down`\, n.
To strike down; to fell; to prostrate by a blow or by blows; as, to knock down an assailant.
To assign to a bidder at an auction, by a blow or knock of the auctioneer's hammer; to sell at an auction; as, the vase was knocked down at two thousand dollars.
To take apart; to dissassemble; as, to knock down a rifle for cleaning.
To reduce or discount the price of; as, the dresses were knocked down to twenty dollars.
To earn (an income). ``plumbers who knock down over a hundred thousand a year.''
Wiktionary
vb. 1 (context transitive English) To hit or knock (something), intentionally or accidentally, so that it falls 2 (context transitive English) To demolish. 3 (context transitive English) At an auction, to declare (something) sold with a blow from the gavel. 4 (context transitive informal English) To reduce the price of. 5 To drink fast 6 (context transitive usually passive English) To disassemble for shipment.
WordNet
Usage examples of "knock down".
Liu Han, Liu Mei, and Nieh Ho-T'ing peered north from a four-story building the little scaly devils somehow hadn't yet managed to knock down.
Their noise filled the Valley, swamping the rush of the river, as they passed over her, heading northeast, high but descending, one, two, three, four silver killers, the summit of mankind's ingenuity deployed to maim illiterate farmers and knock down mud-brick houses and return to base at seven hundred miles per hour.
The ships had had some antimissile launchers added in the years since the Tosevites taught the Race how inadequate its imagination was, but few males thought they could knock down everything.
He actually managed to knock down two sentries who tried to stop him.
I fancy you would master a wish that you had made up your mind it was not quite right to indulge, as easily as you would knock down a drunken fellow who was quarrelsome with you.
Pouncing upon him at night they would snatch away his possessions, knock down his friends who came to his assistance, and scurry away into the darkness.
Seeing her at all would knock down the last critical brick behind which he had dammed up his temper, releasing a flood of emotion that would sweep him away along with everything else.
I bet you a dollar I can knock down eight out of ten pipes in ten shots.