deadening

UK: /ˈdɛd^ənɪŋ/ US: (ded′n ing)

WordReference Random House Unabridged Dictionary of American English © 2025

dead•en•ing  (ded′n ing), n. 

1. a device or material employed to deaden or render dull.
2. a device or material preventing the transmission of sound.
3. a woodland in which the trees are killed by girdling prior to being cleared.

• deaden + -ing¹ 1775–85

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

dead•en /ˈdɛdən/   v. [ ~ + obj]

1. to make less sensitive, intense, strong, or effective:
   pills to deaden pain.
2. to make dull or lifeless:
   The criticism deadened my enthusiasm.

dead•en•ing, adj. 

WordReference Random House Unabridged Dictionary of American English © 2025

dead•en  (ded′n), v.t. 

1. to make less sensitive, active, energetic, or forcible;
   weaken:
   to deaden sound;
   to deaden the senses;
   to deaden the force of a blow.
2. to lessen the velocity of;
   retard:
   to deaden the headway of a ship.
3. to make impervious to sound, as a floor.

v.i. 

4. to become dead.

• dead + -en¹ 1655–65

dead′en•er, n. 
Synonyms

• 1. . blunt, diminish, lessen, numb, dull.

Collins Concise English Dictionary © HarperCollins Publishers::

deaden / ˈdɛd^ən/ verb

1. to make or become less sensitive, intense, lively, etc; damp or be damped down; dull
2. (transitive) to make acoustically less resonant: he deadened the room with heavy curtains

ˈdeadening adjective