In English there are lots of verbs that are made up of two words that don't mean anything close to the real meaning. For example, give up. Give and up themselves have nothing to do with giving up.
Here are some more examples
Throw away- to get rid of, to put in the garbage.
Hang up- to end a phone call
Kick out- to make one get out by force
I just thought it would be hard to memorize this, since it had no relation to do what it actually means.
