knock noun

1 firm sharp sound

ADJ. loud, sharp | gentle, light | determined | timid

VERB + KNOCK hear | answer She hurried to answer the knock at the door.

PHRASES a knock at/on the door There was a loud knock at the door.

2 sharp blow from sth

ADJ. hard, nasty, severe (figurative) the hard knocks of life | minor

VERB + KNOCK get, have, take You've had a nasty knock on the head. (figurative) Their pride took quite a knock when they lost 5?0. | give sb/sth

PREP. ~ on