knock something down

Từ điển Oxford Advanced Learner 8th

▪ I. ˌknock sthˈdown derived
to destroy a building by breaking its walls
Syn: ↑demolish
• These old houses are going to be knocked down.
Main entry: ↑knock_derived
 
▪ II. ˌknock sthˈdown (from sth) (to sth) derived
(informal)to reduce the price of sth
• He knocked down the price from $80 to $50.
see also ↑knock-down
Main entry: ↑knock_derived