rap, wrap

Rap or rap may be a verb ( action word ), meaning to knock lightly or quickly--
He liked to rap his knuckles on the table, even though it annoyed her.
As a  noun ( thing or idea ) rap means a light or sharp knock--
Make sure to give a loud rap on the door, so we'll know it's you.

Rap is also a form of popular music--
Did you hear the new rap song?

Wrap or wrap ( rhymes with rap ) means to cover something on all sides--
Wrap the baby up in a blanket. It's cold out.
Let's buy some paper to wrap the present.

Now that you know that, you can say--
"Give a rap at the door before you come in. I don't want her to look while I wrap the present."

Note--"rap" is also slang for a criminal indictment--
A "bum rap" or a "bad rap" means a false conviction.
To "beat a rap" means to be found not guilty.
Note # 2--to "wrap up" may mean to finish a project or discussion--
Let's wrap this up.
Let's wrap up the meeting by taking questions from the audience.