Don't worry; be insouciant. Perhaps your mind will rest easier if we explain that English speakers learned insouciance (as well as the adjective insouciant) from the French around the early 1800s. The French word comes from a combination of the negative prefix in- and soucier, meaning "to trouble or disturb." Soucier, in turn, traces to sollicitus, the Latin word for "anxious." If it seems to you that sollicitus looks a lot like some other English words you've seen, you're on to something. That root also gave us solicit (which now means "to entreat" but which was once used to mean "to fill with concern or anxiety"), solicitude (meaning "uneasiness of mind"), and solicitous ("showing or expressing concern").
wandered into the meeting with complete insouciance to the fact that she was late
Recent Examples on the WebBlending flair and insouciance, the skirts delivered sensory impact—visual and auditory. Laura Neilson, WSJ, 13 Sep. 2022 Most of these cars are gleaming, and lipstick-red, with the racy insouciance that’s so typical of Italian design. Mark Ellwood, Robb Report, 4 Aug. 2022 The unclipped chinstrap of his off-kilter helmet only added to his air of renegade insouciance. Luke Mogelson, The New Yorker, 23 July 2022 If that cartoon caption strikes you as an Ariana Grande anachronism, that works as part of the film’s insouciance. Owen Gleiberman, Variety, 1 July 2022 Her hard-right activism on so many matters that come before the Court, up to and including the condition of our democracy, and his hand-waving insouciance about it all, have done huge damage to the Supreme Court’s reputation. Michael Tomasky, The New Republic, 28 Mar. 2022 Some of Hollywood’s youngest ingénues were embracing the breezy insouciance of a white shirt, too.Vogue, 27 Mar. 2022 The result has personality to burn, embracing violence, sexuality and an all-around kind of insouciance that rivals fellow doodler Bill Plympton. Peter Debruge, Variety, 25 Mar. 2022 Opt for ample volume, black ribbon, and an air of insouciance—or make like Emily and replace said nonchalance with ready enthusiasm. Calin Van Paris, Vogue, 16 Dec. 2021 See More
Word History
Etymology
French, from in- + soucier to trouble, disturb, from Old French, from Latin sollicitare — more at solicit