deteriorate

UK: /dɪˈtɪəriəreɪt/ US: /dɪˈtɪriəˌreɪt/ ,(di tēr′ē ə rāt′)

Inflections of 'deteriorate' (v): (⇒ conjugate)

deteriorates

v 3rd person singular

deteriorating

v pres p

deteriorated

v past

deteriorated

v past p

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

de•te•ri•o•rate /dɪˈtɪriəˌreɪt/   v. [no object] , -rat•ed, -rat•ing. 

1. to become worse or inferior in character:
   The patient's condition has deteriorated over the last few hours.

de•ter•i•o•ra•tion /dɪˌtɪriəˈreɪʃən/  n. 

[uncountable] The incident triggered the rapid deterioration of peaceful relations.

WordReference Random House Unabridged Dictionary of American English © 2025

de•te•ri•o•rate  (di tēr′ē ə rāt′), v.t., v.i., -rat•ed, -rat•ing. 

1. to make or become worse or inferior in character, quality, value, etc.
2. to disintegrate or wear away.

• Late Latin dēteriōrātus made worse (past participle of dēteriōrāre), equivalent. to Latin dēterior worse (dē from + -ter- formative in adjs. of spatial orientation (compare exterior, interior) + -ior comparative suffix) + -ātus -ate¹
• 1565–75

de•te′ri•o•ra′tive, adj. 
Synonyms

• 1. degenerate, decline, worsen.

Collins Concise English Dictionary © HarperCollins Publishers::

deteriorate / dɪˈtɪərɪəˌreɪt/ verb

1. to make or become worse or lower in quality, value, character, etc; depreciate
2. (intransitive) to wear away or disintegrate

Etymology: 16th Century: from Late Latin dēteriōrāre, from Latin dēterior worse

deˌterioˈration noun

deˈteriorative adjective