To fall by, or as by, the force of gravity; to descend lower and lower; to decline gradually; to subside; as, a stone sinks in water; waves rise and sink; the sun sinks in the west.

To be overwhelmed or depressed; to fall slowly, as so the ground, from weakness or from an overburden; to fail in strength; to decline; to decay; to decrease.

Figuratively: To cause to decline; to depress; to degrade; hence, to ruin irretrievably; to destroy, as by drowping; as, to sink one's reputation.

To make (a depression) by digging, delving, or cutting, etc.; as, to sink a pit or a well; to sink a die.

A shallow depression defect caused by thick wall sections. The material retains heat and shrinks more than normal due to irregular wall thickness.

a depression in the ground communicating with a subterranean passage (especially in limestone) and formed by solution or by collapse of a cavern roof

fall heavily or suddenly; decline markedly; "The real estate market fell off"

a natural depression with no human-sized cave entrance, occasionally with water disappearing into it. Novice cavers typically confuse this with depressions caused by uprooted trees and heavy earth-moving equipment.

Undesired depressions in the surface of a part that are caused by the shrinking of resin as it solidifies. Sink is most common in thick sections of a part. More Info