Word Study
nonchalant
OXFORD DICTIONARY
nonchalant, adj. calm and casual, unmoved, unexcited, indifferent.
Derivative
nonchalance n. nonchalantly adv.
Etymology
F, part. of nonchaloir f. chaloir be concerned
THESAURUS
nonchalant
Laodicean, Olympian, aloof, apathetic, at ease, ataractic, benumbed, blah, blase, calm, careless, casual, cheerful, collected, comatose, composed, cool, degage, desensitized, detached, devil-may-care, disinterested, dispassionate, disregardful, distant, dull, easy, easygoing, effortless, free and easy, glad, happy-go-lucky, heartless, hebetudinous, heedless, hopeless, imperturbable, in a stupor, inattentive, incurious, indifferent, inexcitable, insouciant, lackadaisical, languid, lethargic, light, lighthearted, listless, mindless, negligent, numb, numbed, offhand, passive, perfunctory, phlegmatic, pluckless, pococurante, reckless, regardless, relaxed, resigned, slack, sluggish, smooth, soporific, spiritless, spunkless, stoic, stupefied, supine, together, torpid, turned-off, unanxious, uncaring, unconcerned, undiscriminating, undisturbed, unemotional, unenthusiastic, unexcitable, unexcited, unflappable, uninterested, unmindful, unperturbed, unruffled, unsolicitous, untroubled, withdrawnROGET THESAURUS
nonchalant
Insensibility
N insensibility, insensibleness, moral insensibility, inertness, inertia, vis inertiae, impassibility, impassibleness, inappetency, apathy, phlegm, dullness, hebetude, supineness, lukewarmness, cold fit, cold blood, cold heart, coldness, coolness, frigidity, sang froid, stoicism, imperturbation, nonchalance, unconcern, dry eyes, insouciance, recklessness, callousness, heart of stone, stock and stone, marble, deadness, torpor, torpidity, obstupefaction, lethargy, coma, trance, vegetative state, sleep, suspended animation, stupor, stupefaction, paralysis, palsy, numbness, neutrality, quietism, vegetation, insensible, unconscious, impassive, impassible, blind to, deaf to, dead to, unsusceptible, insusceptible, unimpressionable, unimpressible, passionless, spiritless, heartless, soulless, unfeeling, unmoral, apathetic, leuco-, phlegmatic, dull, frigid, cold blooded, cold hearted, cold as charity, flat, maudlin, obtuse, inert, supine, sluggish, torpid, torpedinous, torporific, sleepy, languid, half-hearted, tame, numbed, comatose, anaesthetic, stupefied, chloroformed, drugged, stoned, palsy-stricken, indifferent, lukewarm, careless, mindless, regardless, inattentive, neglectful, disregarding, unconcerned, nonchalant, pococurante, insouciant, sans souci, unambitious, unaffected, unruffled, unimpressed, uninspired, unexcited, unmoved, unstirred, untouched, unshocked, unstruck, unblushing, unanimated, vegetative, callous, thick-skinned, hard-nosed, pachydermatous, impervious, hardened, inured, casehardened, steeled against, proof against, imperturbable, unfelt, insensibly, aequo animo, without being moved, without being touched, without being impressed, in cold blood, with dry eyes, with withers unwrung, never mind, macht nichts, it is of no consequence, it cannot be helped, nothing coming amiss, it is all the same to, it is all one to.For further exploring for "nonchalant" in Webster Dictionary Online