Why “discomposure” is a great word
A state of agitation, disturbance, or unsettled feeling, particularly as it disrupts one's outward calm or self-possession. From the English prefix dis- (expressing reversal or negation) + composure ("calmness, self-possession"), first recorded in use 1635–45. Unlike "perturbation" (which implies a disturbance traceable to a specific external cause) or "agitation" (which suggests a more active, physically restless churning), discomposure is the quieter, yet unmistakable, loss of internal equilibrium made manifest. It is the teacup rattling in its saucer, the sudden warmth rising beneath the collar, the slight but telling disarray of a previously impeccable collar—the body betraying what the mind cannot yet frame.
Definitions & examples from Wiktionary (CC BY-SA 3.0).