Definition of "deterioration"

deterioration

/dɪˌtɪəɹɪəˈɹeɪʃən/

noun
countable and uncountable, plural deteriorations
1. The process of making or growing worse, or the state of having grown worse.
  Quotations
  The Queen may be celebrating her jubilee but the Queen's English Society, which has railed against the misuse and deterioration of the English language, is to fold.
  2012 June 4, Lewis Smith, “Queen’s English Society says enuf is enough, innit?: Society formed 40 years ago to protect language against poor spelling and grammar closes because too few people care”, in The Guardian‎, London, archived from the original on 10 March 2016
  "The quantum sensors will provide highly accurate measurements that will help to detect the rate of change of the track and subsequently, any deteriorations which might lead to faults."
  2020 November 18, “Network News: Researchers team up on navigation data system”, in Rail, page 23