Entry 2 senses Webster, 1913 operating · IPA /ˈɑpəɹeɪtɪŋ/ 01 adj. pr. p. of operate; as, the operating conditions of the oxidation pond. 1. pr. p. of operate; as, the operating conditions of the oxidation pond. See: operate 2. having an effect or influence. Syn. at work(predicate), in operation, operant.