pit

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

• noun The single central kernel or stone of certain fruits, such as a peach or cherry.
• transitive verb To extract the pit from (a fruit).
• noun A natural or artificial hole or cavity in the ground.
• noun An excavation for the removal of mineral deposits; a mine.
• noun The shaft of a mine.
• noun A concealed hole in the ground used as a trap; a pitfall.
• noun A small indentation in a surface.
• noun A natural hollow or depression in the body or an organ.
• noun A small indented scar left in the skin by smallpox or other eruptive disease; a pockmark.
• noun Zoology Either of a pair of depressions between the nostril and the eye of a pit viper that contain heat-sensing organs.
• noun Botany A cavity in the wall of a plant cell where there is no secondary wall, as in fibers, tracheids, and vessel elements.
• noun Informal An armpit.
• noun An enclosed, usually sunken area in which animals, such as dogs or gamecocks, are placed for fighting.
• noun The section directly in front of and below the stage of a theater, in which the musicians sit.
• noun Chiefly British The ground floor of a theater behind the stalls.
• noun The section of an exchange where trading in a specific commodity is carried on.
• noun The gambling area of a casino.
• noun A sunken area in a garage floor from which mechanics may work on cars.
• noun Sports An area beside an auto racecourse where cars may be refueled or serviced during a race.
• noun Hell. Used with the.
• noun A miserable or depressing place or situation.
• noun Slang The worst. Used with the.
• noun Football The middle areas of the defensive and offensive lines.
• intransitive verb To mark with cavities, depressions, or scars.
• intransitive verb To set in direct opposition or competition.
• intransitive verb To place, bury, or store in a pit.
• intransitive verb To become marked with pits.
• intransitive verb To retain an impression after being indented. Used of the skin.
• intransitive verb To stop at a refueling area during an auto race.

from The Century Dictionary.

• noun The stone of a fruit, as of a cherry or plum.
• A Middle English and Scotch form of put.
• To catch, lay, or bury in a pit.
• To form a little pit or hollow in; mark with little dents, as by the pustules of the smallpox.
• To impress with rounded cup-like hollows, as the mold for a metal casting which is to have rounded bosses on it.
• To put or set in the pit or area for fighting; match as contestants or opponents, one against another, as dogs or cocks: used figuratively of any competitors: generally followed by against.
• To become marked or spotted with pits or depressions; retain the mark of pressure by or as by the fingers: as, in dropsy the skin pits on pressure.
• noun A cavity in the side of the head, between the eye and nostril, found in the poisonous snakes of the subfamily Crotalinæ, whence their name of pit-vipers. This pit is lined with membrane supplied with branches from the trigeminal nerve, but its exact function is not known. See cut under pit-viper
• noun A hole or cavity in the ground, whether natural or made by digging.
• noun Specifically
• noun An excavation or hole in the ground, covered or otherwise concealed, for snaring wild beasts; a pitfall.
• noun A hole dug in the soil of a potato-or turnip-field, for storing potatoes, etc., during the winter. The vegetables stored are usually piled up to some height and covered with earth to keep out the frost.
• noun In horticulture, an excavation in the soil, generally covered by a glazed frame, for protecting tender plants, or for propagation.
• noun In founding, a cavity scooped in the floor to receive cast-metal.
• noun The shaft of a coal-mine, or the mine itself.