Meaning

adjective enjoying or showing or marked by joy or pleasure

adjective marked by good fortune

adjective eagerly disposed to act or to be of service

originFrom Middle English happy (“fortunate, happy”), perhaps an alteration of Middle English happyn, happen (“fortunate, happy”), possibly related to or from Old Norse heppinn (“fortunate, happy”); and potentially assimilated to be equivalent to hap (“chance, luck, fortune”) + -y. Compare also Icelandic heppinn (“lucky”), Faroese heppin (“fortunate, lucky, happy”), Norwegian Nynorsk heppen (“lucky”),…

Etymology from Wiktionary, CC BY-SA 3.0