As adjectives the difference between imperturbable and speedy
is that imperturbable is not easily perturbed, upset or excited while speedy is rapid; swift.
imperturbable
English
Adjective
(head)
not easily perturbed, upset or excited
calm and collected, even under pressure
speedy
English
Adjective
(er)
rapid; swift
Synonyms
* fast, swift, quick, rapid
* See also
Derived terms
* speedily
* speediness
* speedy delete
* speedy deletion