Definition of well

i. A borehole or shaft sunk into the ground for the following purposes: obtaining water, oil, gas, or mineral solutions from an underground source; introducing water, gas, or chemical reagent solutions under pressure into an underground formation; or removing the leachate from such an operation.

See Also: borehole mining

ii. A slot in the front of a hydraulic dredge hull in which the digging ladder pivots.

Ref: Nichols, 1

iii. A hollow cylinder of reinforced concrete, steel, timber, or masonry built in a hole as a support for a bridge or building.

Ref: Webster 3rd

iv. Commonly used as a syn. for borehole or drill hole, esp. by individuals associated with the petroleum-drilling industry.

Ref: Long

v. A wall around a tree trunk that protects it from fill.

Ref: Nichols, 1

vi. An artificial excavation (pit, hole, tunnel), generally cylindrical in form and commonly walled in, sunk (drilled, dug, driven, bored, or jetted) into the ground to such a depth as to penetrate water-yielding rock or soil and to allow the water to flow or to be pumped to the surface; a water well, originally applied to natural springs or pools, esp. mineral spas.

See Also: artesian well, deep well

vii. The crucible of a furnace or a cavity in the lower part of some furnaces to receive falling metal.

viii. The small dark nonreflecting area in the center of a fashioned stone, esp. in a colorless diamond cut too thick.

ix. A vertical opening through the hull of a ship in which drill pipe or mining machinery is lowered to the seafloor, rather than being lowered over the side of the ship. Also called: moonpool.