dampen

UK: /ˈdæmpən/ US: /ˈdæmpən/ ,(dam′pən)

WordReference Random House Learner's Dictionary of American English © 2025

damp•en /ˈdæmpən/   v. 

1. to (cause to) become damp or moistened: [no object]
   The clothes dampened in the humidity.
   [~ + object]
   He dampened the cloth.
2. to (cause to) become dull or depressed: [no object]
   His spirits dampened at the thought.
   [~ + object]
   to dampen one's spirits.

damp•en•er, n. [countable]

WordReference Random House Unabridged Dictionary of American English © 2025

damp•en  (dam′pən), v.t. 

1. to make damp;
   moisten:
   to dampen a sponge.
2. to dull or deaden;
   depress:
   to dampen one's spirits.
3. Music and Dance damp (def. 10).

v.i. 

4. to become damp.

• damp + -en¹ 1620–30

damp′en•er, n. 

Collins Concise English Dictionary © HarperCollins Publishers::

dampen / ˈdæmpən/ verb

1. to make or become damp
2. (transitive) to stifle; deaden

ˈdampener noun