WordNet sense 1 (a concavity in a surface (especially an anatomical depression)):

fossa

WordNet sense 2 (the hard inner (usually woody) layer of the pericarp of some fruits (as peaches or plums or cherries or olives) that contains the seed):

stone, endocarp

WordNet sense 3 (a sizeable hole (usually in the ground)):

cavity

WordNet sense 4 ((Christianity) the abode of Satan and the forces of evil; where sinners suffer eternal punishment):

hell, inferno, perdition, nether region, infernal region

WordNet sense 5 (a trap in the form of a concealed hole):

pitfall

WordNet sense 6 (a surface excavation for extracting stone or slate):

quarry, stone pit

WordNet sense 7 (lowered area in front of a stage where an orchestra accompanies the performers):

orchestra pit

WordNet sense 8 (a workplace consisting of a coal mine plus all the buildings and equipment connected with it):

colliery

WordNet sense 9 (mark with a scar):

mark, pock, scar

WordNet sense 10 (set into opposition or rivalry):

match, oppose