Entry 1 sense Webster, 1913 Vainglorious · Vain·glo·ri·ous · IPA /ˌveɪnˈɡlɔː.ɹi.əs/ 01 a. Feeling or indicating vainglory; elated by vanity; boastful. 1. Feeling or indicating vainglory; elated by vanity; boastful.