Entry 1 sense Webster, 1913 Innocuous /ĭnˌ-äk'-yo͞o-əs/ · In·noc·u·ous · IPA /ɪˈnɑkjuəs/ 01 a. Harmless; producing no ill effect. 1. Harmless; producing no ill effect. “A patient, innocuous, innocent man.” — Burton. “Where the salt sea innocuously breaks.” — Wordsworth.