Definition of "Calm" :

noun: steadiness of mind under stress

noun: wind moving at less than 1 knot; 0 on the Beaufort scale

verb: cause to be calm or quiet as by administering a sedative to

verb: make steady

verb: become quiet or calm, especially after a state of agitation

verb: make calm or still

adjective: (of weather) free from storm or wind

"Calm seas."

adjective: not agitated; without losing self-possession

"Spoke in a calm voice."