Meanings

1. apex
2. crown of the head
3. top
4. roof
5. most
6. to carry on the head
7. to push to the top
8. to go against
9. to replace
10. to substitute
11. to be subjected to (an aerial bombing, hailstorm etc)
12. (slang) to 'bump' a forum thread to raise its profile
13. classifier for headwear, hats, veils etc