imperturbable
adjective
[ ˌɪmpəˈtəːbəb(ə)l ]
• unable to be upset or excited; calm.
• "an imperturbable tranquillity"
Similar:
self-possessed,
composed,
collected,
calm,
cool,
and collected,
as cool as a cucumber,
cool-headed,
self-controlled,
poised,
tranquil,
serene,
relaxed,
easy-going,
unexcitable,
even-tempered,
placid,
sedate,
phlegmatic,
unperturbed,
unflustered,
untroubled,
unbothered,
unruffled,
undismayed,
unagitated,
undisturbed,
unmoved,
nonchalant,
at ease,
unflappable,
unfazed,
together,
laid-back,
nonplussed,
equanimous,
Origin:
late Middle English: from late Latin imperturbabilis, from in- ‘not’ + perturbare (see perturb).
