bottom

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

• noun The deepest or lowest part.
• noun The part closest to a reference point.
• noun The underside.
• noun The supporting part; the base.
• noun The far end or part.
• noun The last place, as on a list.
• noun The lowest or least favorable position.
• noun The basic underlying quality; the source.
• noun The solid surface under a body of water.
• noun Low-lying alluvial land adjacent to a river.
• noun Nautical The part of a ship's hull below the water line.
• noun A ship; a boat.
• noun The trousers or short pants of pajamas.
• noun Informal The buttocks.
• noun The seat of a chair.
• noun Baseball The second or last half of an inning.
• noun Staying power; stamina. Used of a horse.
• noun Slang One who is penetrated by another person or is the submissive partner in a sexual encounter or relationship.
• adjective Situated at the bottom.
• adjective Of the lowest degree, quality, rank, or amount.
• intransitive verb To provide with an underside.
• intransitive verb To provide with a foundation; base.
• intransitive verb To have or strike the underside against something.
• idiom (at bottom) Basically.

from The Century Dictionary.

• In botany, to form a bulb or other underground expansion, as an onion.
• In gold-mining, to get to the bed-rock, or clay, below which it is useless to sink.
• To furnish with a bottom: as, to bottom a shoe or a chair.
• To found or build upon; fix upon as a support; base.
• To fathom; reach or get to the bottom of.
• To wind round something, as in making a ball of thread.
• In dyeing, to dye first with a certain color in preparation for another.
• To rest; be based.
• To strike against the bottom or end: as, a piston bottoms when it strikes against the end of the cylinder.
• noun The lowest landing in a shaft or incline; the lowest working in a mine.
• noun The lower portion of a seam or bed, as of coal.
• noun In gold-mining, the old river-bed upon which the wash-dirt rests, and upon which the richest alluvial gold is found. Sometimes called the gutter.
• noun In golf, a backward rotation of the ball which tends to check its motion after it touches the ground.
• noun In saddlery, the portion of a martingale which passes between the horse's belly and the belly-band.
• noun The lowest or deepest part of anything, as distinguished from the top; utmost depth, either literally or figuratively; base; foundation; root: as, the bottom of a hill, a tower, a tree, of a well or other cavity, of a page or a column of figures.
• noun The ground under any body of water: as, a rocky bottom; a sandy bottom; to lie on the bottom of the sea.
• noun In physical geography, the low land adjacent to a river, especially when the river is large and the level area is of considerable extent. Also called bottom-land.
• noun In mining, that which is lowest; in Pennsylvania coal-mining, the floor, bottom-rock, or stratum on which a coal-seam rests.
• noun The lower or hinder extremity of the trunk of an animal; the buttocks; the sitting part of man.
• noun The portion of a chair on which one sits; the seat.
• noun That part of a ship which is below the wales; hence, the ship itself.
• noun The heavy impurities which collect at the bottoms of vessels in which fluids are left to settle: as, “the bottom of beer,”
• noun plural The residuum, consisting of impure metal, often found at the bottom of a smelting-furnace when the operation has not been skilfully conducted: chiefly used in reference to copper-smelting.