tranquil Synonyms

still calm quiet serene unruffled placid smooth unagitated stoical stolid stormless temperate unmoved waveless windless soundless stilly stiller smoother somnolent soothing soothe unflappable staid steady phlegmatic undisturbed to quiet level-headed unsurprised imperturbable at ease even-tempered unexcitable untroubled self-controlled unemotional unexcited unflustered nonviolent nonbelligerent unalarming at peace peace of mind laid-back easygoing levelheaded unworried mild-mannered mirrorlike