Synonyms of insouciant

adjectiveCasually unconcerned; carefree, indifferent, nonchalant.

• blaséUnimpressed, indifferent, especially because of overfamiliarity.
• uninterestedNot interested; indifferent, not concerned.
• adiaphroistic
• apathetic
• apathisticalApathetic; unemotional.
• blithe
• deaf
• cool
• shiftless
• dispassionateNot showing, and not affected by, emotion, bias, or prejudice.
• dull
• enervatedWeakened, debilitated or deprived of strength or vitality.
• gallionic
• halfheartedLacking full energy, effort, commitment, or resolve.
• impassiveHaving, or revealing, no emotion.
• ineffervescibleNot effervescible.
• indifferentAmbivalent; unconcerned; uninterested, apathetic.
• insensibleIncapable of mental feeling; indifferent.
• jadedBored or lacking enthusiasm, typically after having been overexposed to, or having consumed too much of something.
• languidOf a person or their actions, character, etc.: lacking drive, emotion, or enthusiasm; apathetic, listless, spiritless...
• languorousLacking energy, spirit, liveliness or vitality; languid, lackadaisical.
• lethargicIndifferent, apathetic.
• listlessLacking energy, enthusiasm, or liveliness.
• lackadaisicalShowing no interest, vigor, determination, or enthusiasm.
• lotophagousRelating to the Lotophagi (lotus eaters).
• lukewarmUnenthusiastic (about a proposal or an idea).
• mehApathetic; unenthusiastic.
• mopeyGiven to moping; in a depressed condition, low in spirits; lackadaisical.
• nonchalant
• nonplussed USUnaffected, unfazed; unimpressed.
• otioseOf a person, possessing a bored indolence.
• phlegmaticNot easily excited to action or passion; calm; sluggish.
• pococuranteApathetic, indifferent or nonchalant.
• spiritlessLacking energy, drive, motivation or emotion. Enervated.
• supineReluctant to take action due to indifference or moral weakness; apathetic or passive towards something.
• tepidUninterested; exhibiting little passion or eagerness; lukewarm.
• torpidLazy, lethargic or apathetic.
• unarousedNot aroused.
• uncaringCharacterized by a lack of care; not caring.
• unconcernedIndifferent and having no interest; aloof.
• unenthusiasticWithout enthusiasm; unexcited.
• unimpressibleNot impressible; not sensitive; apathetic.
• unlivelyNot lively.
• unmovedNot affected emotionally, or not showing emotion.
• untouchedNot influenced, affected or swayed.
• unzealousNot zealous.
• world-wearyBored with life.
• airy
• at ease
• at peace
• carefreeWithout cares or worries; free of concern or worries; without difficulty.
• casualCareless.
• chillCalm, relaxed, easygoing.
• devil-may-careCarefree, reckless, irresponsible.
• easy-breezyLaid-back and uncomplicated.
• easygoingCalm, relaxed, casual and informal.
• happy-go-luckyCarefree or untroubled.
• laid-backRelaxed and easy‐going; demonstrating an absence of stress or worry.
• leisurelyCharacterized by leisure; taking plenty of time; unhurried.
• lightheartedEnjoyably lacking of seriousness, not grave.
• loose
• mellowCheerful, genial, jovial, merry; also, easygoing, laid-back, calm, relaxed.
• offhand
• relaxedFree from tension or anxiety; at ease; leisurely.
• sereneWithout worry or anxiety; unaffected by disturbance.
• soluteRelaxed; hence, cheerful, merry.
• tranquil
• unanxiousNot anxious.
• unbotheredNot bothered, serene.
• undisturbed
• unruffled
• untroubledWithout worries; free from care.
• unworriedFree of worries.
• heartless rareListless, unenthusiastic.
• Laodicean archaicHalf-hearted or apathetic, especially with regards to religion or politics.
• torpedinous archaicStupefying; dull; torpid.
• careless archaicFree from care; unworried, without anxiety.
• wanton obsoletePlayful, sportive; merry or carefree.