1. subst. A knob or disc that is passed through a loop or (buttonhole), serving as a fastener.
April fastened the buttons of her overcoat to keep out the wind.
2. subst. A mechanical device meant to be pressed with a finger in order to open or close an electric circuit or to activate a mechanism.
Pat pushed the button marked "shred" on the blender.
3. subst. (graphical user interface) An on-screen control that can be selected as an activator of an attached function.
Click the button that looks like a house to return to your browser's home page.
4. subst. (US) A badge worn on clothes, fixed with a pin through the fabric.
The politician wore a bright yellow button with the slogan "Vote Smart" emblazoned on it.
5. subst. (botany) A bud.
6. subst. (slang) The clitoris.
7. subst. (curling) The center (bullseye) of the house.
8. subst. (fencing) The soft circular tip at the end of a foil.
9. subst. (poker) A plastic disk used to represent the person in last position in a poker game; also dealer's button.
10. subst. (poker) The player who is last to act after the flop, turn and river, who possesses the button.
11. subst. A raised pavement marker to further indicate the presence of a pavement marking painted stripe.
12. subst. (South Africa, slang) A methaqualone tablet (used as a recreational drug).
13. subst. A piece of wood or metal, usually flat and elongated, turning on a nail or screw, to fasten something, such as a door.
14. subst. A globule of metal remaining on an assay cupel or in a crucible, after fusion.
15. subst. A knob; a small ball; a small, roundish mass.
16. subst. A small white blotch on a cat's coat.
17. subst. (archaic) A unit of length equal to 1/12 of an inch.
18. subst. The means for initiating a nuclear strike or similar cataclysmic occurrence.
19. subst. (lutherie) In a violin-family instrument, the near semi-circular shape extending from the top of the back plate of the instrument, meeting the heel of the neck.
20. subst. (lutherie) (synonym of endbutton).
21. subst. (lutherie, bowmaking) (synonym of adjuster).
22. subst. The least amount of care or interest; a whit or jot.
23. subst. (comedy) The final joke at the end of a comedic act (such as a sketch, set, or scene).
Your sketch was hilarious but the button didn't even make me laugh, which is a problem; the button should be the strongest line in your scene.
24. v. To fasten with a button.
25. v. (intransitive) To be fastened by a button or buttons.