Origin: 1350–1400; (n., adj.) ME
calm(
e) < It
calma (n.),
calmo (adj.) < LL
cauma summer heat (with
l perh. from L
calēre to be hot) < Gk
kaûma (s.
kaumat-) burning heat; akin to
kaíein to burn (
see caustic ); (v.) ME
calmen < It
calmare, deriv. of the n.
Related forms: calm⋅ing⋅ly, adverb
calmly, adverb
calmness, noun
Synonyms:
1. quiet, motionless. 3. placid, peaceful, serene, self-possessed. Calm, collected, composed, cool imply the absence of agitation. Calm implies an unruffled state, esp. under disturbing conditions: calm in a crisis. Collected implies complete inner command of oneself, usually as the result of an effort: He remained collected in spite of the excitement. One who is composed has or has gained dignified self-possession: pale but composed. Cool implies clarity of judgment along with apparent absence of strong feeling or excitement, esp. in circumstances of danger or strain: so cool that he seemed calm. 7. still, quiet, tranquilize; allay, assuage, mollify, soothe, soften.
Antonyms:
2. tempestuous. 3. agitated.
[kahm; older kam; spelling pron. kahlm] 
adjective, -er, -est, noun, verb