Plain English Meaning
Damping is what stops something from wobbling or overshooting. It calms the movement down so the pointer or part settles steadily on the right value.
Full Definition
The progressive reduction or suppression of unwanted oscillation, vibration, or motion in an instrument or system, so that the moving element settles smoothly to its correct reading instead of swinging back and forth.
Context Anchor
Seen in instrument discussions such as the turn-and-slip indicator, where the ball or pointer must move freely but not bounce so much that it becomes hard to read.
Derivation
From the older English 'damp,' meaning to deaden or muffle. The same root that gives us 'dampen a sound' is used here to describe deadening unwanted motion.