Oxford Dictionary English oxidation noun noun BrE BrE//ˌɒksɪˈdeɪʃn// ; NAmE NAmE//ˌɑːksɪˈdeɪʃn// [uncountable] (chemistry) Add to my wordlistjump to other resultsthe process of oxidizing or being oxidized compare reduction (4)See oxidation in the Oxford Learner's Dictionary of Academic EnglishCheck pronunciation: oxidation oxfordlearnersdictionaries.com