calm calm /ˈkɑːlm/

adjective

1. () Not agitated; without losing self-possession  ( serene , tranquil , unagitated , calm )
   not agitated; without losing self-possession
    Spoke in a calm voice
   spoke in a calm voice
    Remained calm throughout the uproar
   remained calm throughout the uproar
    He remained serene in the midst of turbulence
   he remained serene in the midst of turbulence
    A serene expression on her face
   a serene expression on her face
    She became more tranquil
   she became more tranquil
    Tranquil life in the country
   tranquil life in the country
   
2. (of weather) free from storm or wind  ( calm )
   (of weather) free from storm or wind
    Calm seas
   calm seas
   

noun

1. () Steadiness of mind under stress  ( collectedness , unflappability , equanimity , calm , calmness , composure )
   steadiness of mind under stress
    He accepted their problems with composure and she with equanimity
   he accepted their problems with composure and she with equanimity
   
2. Wind moving at less than 1 knot; 0 on the Beaufort scale  ( calm , calm air )
   wind moving at less than 1 knot; 0 on the Beaufort scale
   

verb

1. () Make calm or still  ( calm down , lull , quieten [British] , calm , quiet , still , tranquilize [ N. American] , tranquillise [British] , tranquillize )
   make calm or still
    Quiet the dragons of worry and fear
   quiet the dragons of worry and fear
   
2. () Make steady  ( becalm , calm , steady )
   make steady
    Steady yourself
   steady yourself
   
3. Cause to be calm or quiet as by administering a sedative to  ( calm , sedate , tranquilize [ N. American] , tranquillise [British] , tranquillize )
   cause to be calm or quiet as by administering a sedative to
    The patient must be sedated before the operation
   The patient must be sedated before the operation
   
4. Become quiet or calm, especially after a state of agitation  ( calm , chill out [Informal] , cool it [Informal] , calm down , cool off , settle down , simmer down , take a chill pill [Informal] )
   become quiet or calm, especially after a state of agitation
    After the fight both men need to cool off.
   After the fight both men need to cool off.
    It took a while after the baby was born for things to settle down again.
   It took a while after the baby was born for things to settle down again.