instantly /ˈɪnstəntli/adverb 3conjunction 1 adverb3 •at once, with no time passing in betweenWhen the neighbours' dog barked, ours instantly replied with a howl. •(no longer used) Urgently; with insistence.Sir, my lord would instantly speak with you. — 1602 •(no longer used) At the same time.As if he mastred there a double spirit Of teaching, and of learning instantly — 1597 conjunction1 •As soon as, directly.I phoned instantly I heard you were back.