pit

a sizeable hole (usually in the ground); "they dug a pit to bury the body"

a concavity in a surface (especially an anatomical depression)

the hard inner (usually woody) layer of the pericarp of some fruits (as peaches or plums or cherries or olives) that contains the seed; "you should remove the stones from prunes before cooking"

(Christianity) the abode of Satan and the forces of evil; where sinners suffer eternal punishment; "Hurl'd headlong...To bottomless perdition, there to dwell"- John Milton; "a demon from the depths of the pit"; "Hell is paved with good intentions"-Dr. Johnson

a trap in the form of a concealed hole

a surface excavation for extracting stone or slate; "a British term for `quarry' is `stone pit'"

set into opposition or rivalry; "let them match their best athletes against ours"; "pit a chess player against the Russian champion"; "He plays his two children off against each other"