A Cap

1. A close-fitting hat, either brimless or peaked.

Hyponyms: headgear

2. A special hat to indicate rank, occupation, etc.
3. An academic mortarboard.
4. A protective cover or seal.
5. A crown for covering a tooth.
6. The summit of a mountain, etc.
7. An artificial upper limit or ceiling.

Antonym: floor

8. The top part of a mushroom.
9. (toy) A small amount of percussive explosive in a paper strip or plastic cup for use in a toy gun.
10. A small explosive device used to detonate a larger charge of explosives.
11. (slang) A bullet used to shoot someone.
12. (soccer) An international appearance.
13. (obsolete) The top, or uppermost part; the chief.
14. (obsolete) A respectful uncovering of the head.
15. (zoology) The whole top of the head of a bird from the base of the bill to the nape of the neck.
16. (architecture) The uppermost of any assemblage of parts.
17. Something covering the top or end of a thing for protection or ornament.
18. (nautical) A collar of iron or wood used in joining spars, as the mast and the topmast, the bowsprit and the jib boom; also, a covering of tarred canvas at the end of a rope.
19. (geometry) A portion of a spherical or other convex surface.
20. A large size of writing paper.
21. (African-American Vernacular) A lie or exaggeration