From Longman Dictionary of Contemporary Englishknock somebody/something down phrasal verb1 hit/push somebody knock somebody ↔ down to hit or push someone so that they fall to the ground Something hit him from behind and knocked him down. → knockdown22 hit somebody with a vehicle knock somebody ↔ down to hit someone with a vehicle while you are driving, so that they are hurt or killed A child was in hospital last night after being knocked down by a car.3 destroy knock something ↔ downDESTROY to destroy a building or part of a building SYN demolish They want to knock the house down and rebuild it.4 reduce price knock something ↔ down informalREDUCE to reduce the price of something by a large amount The new stove we bought was knocked down from $800 to $550. → knockdown15 ask somebody to reduce price knock somebody down to something informalREDUCE to persuade someone to reduce the price of something they are selling you She’s asking for £150 but I’ll try to knock her down to £100. → knock→ See Verb table
Examples from the Corpus
knock somebody down to something• Rose recommended knocking it down to $ 15,000 and the supes agreed.• But prolonged recession and high unemployment knocked his popularity down to rock-bottom.From Longman Business Dictionaryknock something → down phrasal verb [transitive]1informal to reduce the price of something so that it is very cheapVolkswagen has knocked down the prices of the base GL model this year.2be knocked down to somebody to be sold at an AUCTION (=a sale where something is sold to the person willing to pay most)The item was finally knocked down for £790 to a bidder in the saleroom. → knock→ See Verb table 