insolitement, adv., unusually.
insolubilité, n.f., insolubility.
insoluble, adj., insoluble.
insolvabilité, n.f., insolvency.
insolvable, adj., insolvent.
insomnie (in-som-nî), n.f., sleeplessness, wakefulness; insomnia. Heures d’—; sleepless nights.
insondable, adj., unfathomable; fathomless.
insouciance, n.f., carelessness, thoughtlessness, heedlessness, listlessness.
insouciant, -e, adj., careless, thoughtless, heedless, listless, indifferent.
insoucieu-x, -se, adj., careless, free from care.