Synonyms of unflappable

Adjective

1. imperturbable, unflappable, composed (vs. discomposed)

usage: not easily perturbed or excited or upset; marked by extreme calm and composure; "hitherto imperturbable, he now showed signs of alarm"; "an imperturbable self-possession"; "unflappable in a crisis"

Definition and meaning of unflappable (Dictionary)