adj. 25B6; adjective
an unruffled voice : CALM, composed, self-controlled, self-possessed, untroubled, unperturbed, at ease, relaxed, serene, cool, {cool, calm, and collected}, cool-headed, unemotional, equanimous, equable, stoical; informal unfazed.
an unruffled sea : TRANQUIL, calm, smooth, still, flat, motionless, placid, waveless, pacific, like a millpond.