present participle of knock at the door of

present participle of knock on the door of

(military) The practice of dropping a nonexplosive or low-yield device on a target around 10 to 15 minutes before a bombing in order to caution any civilians present to flee, so as to minimize civilian casualties.

present participle of knock on the head

present participle of knock it off

One of a class of childish jokes told as a dialog, and usually including a pun, in the following form:

An arrangement between multiple insurance companies in which each company pays the losses incurred by its own policyholders in an event, regardless of who was at fault (now rarely used outside of motor insurance).

plural of knock-knock joke

plural of knock knock joke

Alternative spelling of knock-knock joke