ETYM Old Eng. calme, French calme, from Italian or Spanish calma (cf. Portu. calma heat), prob. from Late Lat. cauma heat, from Greek kayma burning heat, from kaiein to burn. Related to Caustic.
Freedom from motion, agitation, or disturbance; tranquility; stillness; quiet; serenity.

1. A feeling of calm; an absence of agitation or excitement.
2. An absence of strong winds or rain.

(Poetic) Tranquil silence; SYN. stillness, still.

ETYM French, from Latin silentium. Related to Silent.
1. The absence of sound; SYN. quiet.
2. The state of being silent (as when no one is speaking).

Calmness without winds; SYN. windlessness.

ETYM French tranquillité, Latin tranquillitas.
1. A state of peace and quiet; SYN. tranquility, quietness, quietude.
2. An untroubled state; free from disturbances; SYN. quiet.