deterioration

Noun

Synonyms: impairment decline in quality declension worsening

WordNet 3.0

Noun (2)

a symptom of reduced quality or strengthSynonyms: impairment
process of changing to an inferior stateSynonyms: decline in quality declension worsening

Webster's Dictionary (GCIDE)

Deterioration \De*te`ri*o*ra"tion\, n. [LL. deterioratio: cf. F. d['e]t['e]rioration.] The process of growing worse, or the state of having grown worse. [1913 Webster]