spot

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A mark on a surface differing sharply in color from its surroundings.
• noun A blemish, mark, or pimple on the skin.
• noun A stain or blot.
• noun A mark or pip on a playing card; a spade, club, diamond, or heart.
• noun A playing card with a specified number of such marks on it indicating its value.
• noun Informal A piece of paper money worth a specified number of dollars.
• noun A small area.
• noun A location or position.
• noun A point of interest.
• noun A position or an item in an ordered arrangement.
• noun Football The position of the ball for the line of scrimmage as determined by a referee after a play.
• noun Informal A situation, especially a troublesome one.
• noun A flaw in one's reputation or character.
• noun A short presentation or commercial on television or radio between major programs.
• noun Informal A spotlight.
• noun A small croaker (Leiostomus xanthurus) of North American Atlantic waters, having a dark mark above each pectoral fin and valued as a food and game fish.
• noun Chiefly British A small amount; a bit.
• intransitive verb To cause a spot or spots to appear on, especially.
• intransitive verb To soil with spots.
• intransitive verb To decorate with spots; dot.
• intransitive verb To bring disgrace to; besmirch.
• intransitive verb To place in a particular location; situate precisely.
• intransitive verb Football To position (the ball) determining the line of scrimmage after a play has been completed.
• intransitive verb To detect or discern, especially visually; spy.
• intransitive verb To remove spots from, as in a laundry.
• intransitive verb Sports To yield a favorable scoring margin to.
• intransitive verb Sports To act as a spotter for (a gymnast, for example).
• intransitive verb Informal To lend.
• intransitive verb To become marked with spots.
• intransitive verb To cause a discoloration or make a stain.
• intransitive verb To locate targets from the air during combat or training missions.
• adjective Made, paid, or delivered immediately.
• adjective Of, relating to, or being a market in which payment or delivery is immediate.
• adjective Involving random or selective instances or actions.
• adjective Presented between major radio or television programs.
• idiom (in spots) Now and then; here and there; occasionally.
• idiom (on the spot) Without delay; at once.
• idiom (on the spot) At the scene of action.
• idiom (on the spot) Under pressure or attention; in a pressed position.

from The Century Dictionary.

• To make a spot on; blot; stain; discolor or defile in a spot or spots.
• To mar the perfection or moral purity of; blemish; tarnish; sully.
• To mark or cover with spots; mark in spots: dot.
• Specifically To put a patch or patches on (the face) by way of ornament.
• To mark as with a spot; especially, to note as of suspicious or doubtful character. Tuft's Glossary of Thieves' Jargon (1798).
• To note or recognize by some peculiarity; catch with the eye; detect; come upon; find out.
• In horse-racing, to indicate, give a hint as to, or name: as, to spot the winner of a future race.