verb (used with object)
- to make damp; moisten: to dampen a sponge.
- to dull or deaden; depress: to dampen one’s spirits.
- damp(def 10).
verb (used without object)
- to become damp.
- to make or become damp
- (tr) to stifle; deaden
v.1630s, “to dull or deaden” (of force, enthusiasm, ardor, etc.), from damp (adj.) + -en (1). Meaning “to moisten” is recorded from 1827. Related: Dampened; dampening.