happy-go-luckyEnglishOxford American Thesaurushappy-go-lucky adjective their casual, happy-go-lucky manner: easygoing, carefree, casual, free and easy, devil-may-care, blithe, nonchalant, insouciant, blasé, unconcerned, untroubled, unworried, lighthearted; heedless, reckless, irresponsible, improvident; informal slaphappy, laid-back. ▷antonyms anxious; serious.