Some examples and use cases from the internet:

Some examples and use cases from the internet:

• 1[countable] a quick sharp hit or knock There was a sharp rap on the door. 2 [ uncountable] a type of popular music with a fast strong rhythm and words which are spoken fast, not sung a rap song/artist Culture Rap music first became popular in ...
• [countable] the sound produced by such a blow:a rap on the door. Slang Terms[ uncountable][Slang.]blame or punishment:not going to take the rap for your mistakes. Slang Terms[countable][Slang.]a criminal charge:a murder rap.
• 1. blow, knock, crack, tap, clout (informal) There was a light rap on the door. 2. ( Slang) rebuke, sentence, blame, responsibility, punishment, censure, chiding You'll be facing a federal rap for aiding and abetting an escaped convict.
• 1[countable] a quick sharp hit or knock There was a sharp rap on the door. 2[ uncountable] a type of popular music with a fast strong rhythm and words that are spoken fast, not sung a rap song/artist; 3[countable] a rap song; 4 [countable] ...

• Let's knock on the door and ask why they sent that note.
• If someone's taking too long, come knock on the door.
• It would have been easier to knock on the door than to write.
• At noon, come knock on the door.
• A knock on the door interrupts them.
• A knock on the door is all you'd get.
• I still get nervous when there's a knock on the door.
• Following a knock on the door, a mailman falls into their flat.