A knob or disc that is passed through a loop or (buttonhole), serving as a fastener. • A mechanical device designed to be pressed with a finger in order to open or close an electric circuit or to activate a mechanism. • An on-screen control that can be selected as an activator of an attached function. • A badge worn on clothes, fixed with a pin through the fabric. • A bud. • The calyx of an orange. • The head of an unexpanded mushroom. • The clitoris. • The center (bullseye) of the house. • The soft circular tip at the end of a foil. • A plastic disk used to represent the person in last position in a poker game; also dealer's button. • The player who is last to act after the flop, turn and river, who possesses the button. • A person who acts as a decoy. • A raised pavement marker to further indicate the presence of a pavement-marking painted stripe. • The end of a runway. • A methaqualone tablet (used as a recreational drug). • A piece of wood or metal, usually flat and elongated, turning on a nail or screw, to fasten something, such as a door. • A globule of metal remaining on an assay cupel or in a crucible, after fusion. • A knob; a small ball; a small, roundish mass. • A small white blotch on a cat's coat. • A unit of length equal to ¹⁄₁₂ inch. • The means for initiating a nuclear strike or similar cataclysmic occurrence. • The oblate spheroidal mass of glass attaching a stem to either its bowl or foot. • In an instrument of the violin family, the near-semicircular shape extending from the top of the back plate of the instrument, meeting the heel of the neck. • Synonym of endbutton, part of a violin-family instrument. • Synonym of adjuster. • The least amount of care or interest; a whit or jot. • The punchy or suspenseful line of dialogue that concludes a scene. • The final joke at the end of a comedic act (such as a sketch, set, or scene). • A button man; a professional assassin. • The final segment of a rattlesnake's rattle. • A clove (of garlic). • Pedicle; the attachment point for antlers in cervids.