calmest
calm-est
adjective
Having or showing the least agitation, excitement, or disturbance; most tranquil.
"She was the calmest person in the room."
Thesaurus
Synonyms: tranquillize, tranquillise, tranquilize, calm down, still, lull, quiet, calm, quieten, sedate, calm air, equanimity
Antonyms: agitate, arouse, brace, charge, charge up, commove, discomposure, energise, energize, excite, perk up, rouse