cool as a cucumber
coolness
imperturbability
imperturbableness
calm
compose
keep one's pants on
calmness
have one's wits about one
still
quiet
quieten
lull
tranquillize
calm down
tranquillise
equanimous
tranquilize
cucumber
calmen
countenance
self-possession
keep one's knickers on
reposed
settle
sile
tranquillizingly
keep one's hair on
lown
cool
calmative
unfrenzied
bestill
centered
keep one's head
salve
hold one's nerve
pour oil on troubled waters
composure
calmish
chill
placid
unfrazzled
peacen
unpanicked
complacently
halcyon
heropanti
encalm
coolheaded