1. keep on doing sth
to continue to do something, or to do something again and again
Dictionary example:
- She kept on asking me questions the whole time.
- I kept on looking for him outside my building and in the park, but I still [haven't found] him.
2. keep (sb/sth) out
to not go into a place, or to stop someone or something from going into a place
Dictionary example:
- The building was unsafe so they put up a sign saying 'Danger - Keep out'.
3. keep up sth or keep sth up
to not allow something that is at a high level to fall to a lower level
Dictionary examples:
- Keep up the good work!
- Make sure you eat properly - you've got to keep your strength up.
- I joined because I wanted to keep up [my] English and also, to learn some more.
4. knock sb down
to hit someone with a vehicle and injure or kill them
Dictionary example:
- She was knocked down by a bus.
- The man explained that Lime was knocked down by a car and that he died immediately.
5. laugh at sb/sth
to show that you think someone or something is stupid
Dictionary examples:
- I can't go into work looking like this - everyone will laugh at me.
- If you say that, people will just laugh at you.
- All my friends laughed at me.