Answer: tranquil

AnswerCrossword Clue
TRANQUILSerene
TRANQUILHalcyon
TRANQUILFree from turmoil
TRANQUILQuiet and calm
TRANQUILStill
TRANQUILPacific
TRANQUILUnruffled
TRANQUILPeaceful
tranquilcalm and peaceful
tranquilpeaceful; calm