Entry 1 sense Webster, 1913 Arbitrarily /är'-bĭt-rĕrˌ-əl-ē/ · Ar·bi·tra·ri·ly · IPA /ˈɑrbɪtrˌɛrəliː/ 01 adv. In an arbitrary manner; by will only; despotically; absolutely. 1. In an arbitrary manner; by will only; despotically; absolutely.