n.1. A deep hole or shaft sunk into the earth to obtain water, oil, gas, or brine.
2. A container or reservoir for a liquid, such as ink.
3. a. A place where water issues from the earth; a spring or fountain.
b. A mineral spring.
c. wells A watering place; a spa.
4. An abundant source: a well of information.
5. An open space extending vertically through the floors of a building, as for stairs or ventilation.
6. Nautical a. An enclosure in a ship's hold for the pumps.
b. A compartment or recessed area in a ship, used for stowage: an anchor well.
c. A part of a ship's weather deck enclosed between two watertight bulkheads.
7. A cistern with a perforated bottom in the hold of a fishing vessel for keeping fish alive.
8. An enclosed space for receiving and holding something, such as the wheels of an airplane when retracted.
9. Chiefly British The central space in a law court, directly in front of the judge's bench, where the counsel or solicitor sits.
v.intr.1. To rise to the surface, ready to flow: Tears welled in my eyes.
2. To rise or surge from an inner source: Anger welled up in me.