Englishlaid-back
adjective informal
relaxed, at ease, easy-going, equable, free and easy, easy, casual, informal, friendly, nonchalant, insouciant, unexcitable, imperturbable, unemotional, unruffled, blasé, blithe, cool, collected, cool, calm, and collected, calm, composed, self-possessed, level-headed, self-controlled, unperturbed, unflustered, unworried, unconcerned, placid, peaceful, tranquil, serene, low-key, understated, downbeat;
leisurely, unhurried;
stoical, phlegmatic, mellow, forbearing, live-and-let-live, tolerant;
informal unflappable, together, chilled;
North American, informal nonplussed.
▷antonyms tense, edgy, uptight.
laid-back Oxford Dictionary of English