to knock on a door

to rip off

to beat sb

to come to a decision

to think over

to pound

lit. a brick as a door knocker (idiom); fig. a temporary expedient

to key in

back-knocking massage

to back sb up

extortion by taking advantage of sb's weakness

to press (fruit)

to sound a bell

extortion

to get sth open by tapping or striking it

to sound a bell

percussions

to receive oral sex from a prostitute

(neologism) (slang) to impatiently await

Literally: to extort extra money from the client by slowing down the progress, pretending the task is too hard to finish. It came from the dock coolies in previous time, when dishonest coolies want more payment, they would halt the loading and sit aside tapping their shanks, imply to the client they want more money before continue. Literally: tap the shank

to beat a gong

to make insinuations

a knell