calm, peaceful, or tranquil; unruffled

a serene landscape; serene old age.

clear; fair

serene weather.

( usually initial capital letter ) most high or august (used as a royal epithet, usually prec. by his, your, etc.)

His Serene Highness.

serenity; tranquillity.

Archaic . a clear or tranquil expanse of sea or sky.

adjective

agitated , disturbed , excited , troubled

adjective

at peace , clear , collected , comfortable , composed , content , cool * , cool as a cucumber , dispassionate , easy , easygoing , fair , halcyon , imperturbable , laid-back * , limpid , patient , peaceful , pellucid , phlegmatic , placid , poised , quiescent , quiet , reconciled , resting , satisfied , sedate , self-possessed , smooth , still , stoical , tranquil , unflappable , unruffled , untroubled , calm , stilly , august , bright , cool , impassive , steady , unclouded , undisturbed , unobscured , unperturbed