Identification definition: an act or instance of identifying; the state of being identified.. See examples of IDENTIFICATION used in a sentence. UIDAI is mandated to issue an easily verifiable 12 digit random number as Unique Identity - Aadhaar to all Residents of India. IDENTIFICATION definition: 1. the act of recognizing and naming someone or something: 2. an official document that shows or…. Learn more. Synonyms for IDENTIFICATION: ID, document, documentation, verification, validation, authentication, evidence, proof; Antonyms of IDENTIFICATION: rebuttal, refutation ...