Wiktionary(0.00 / 0 votes)Rate this definition: 1  ha(Verb) Alternate spelling of a. 2  ha(Interjection) A representation of laughter. 3  ha(Interjection) An exclamation of triumph or discovery. 4  ha(Verb) Alternate spelling of a. 5  Ha(ProperNoun) An ethnic and linguistic group based in Kigoma Region in western Tanzania.