Definitions of calm:

• noun:   steadiness of mind under stress
• verb:   become quiet or calm, especially after a state of agitation
• verb:   make calm or still
• verb:   cause to be calm or quiet as by administering a sedative to
• verb:   make steady
• adjective:   characterized by absence of emotional agitation

  Example: "Calm acceptance of the inevitable"

• adjective:   marked by freedom from agitation or excitement

  Example: "The rioters gradually became calm and slowly dispersed"

• adjective:   (of weather) free from storm or wind

  Example: "Calm seas"

• adjective:   not agitated; without losing self-possession

  Example: "Spoke in a calm voice"