безмятежность

Жен. insouciance, placidity, serenity безмятежн|ость — ж. serenity, tranquillity, placidity; ~ый serene, placid, unruffled; ~ый покой unruffled serenity, undisturbed tranquillity; ~ый сон tranquil/untroubled slumber; ~ое детство unruffled childhood.