Un-perturbed, meaning not disturbed or affected by something, can have several antonyms depending on the context. Some of these antonyms include nervous, agitated, worried, anxious, unsettled, disturbed, perturbed, and shaken. For example, if someone is unperturbed by a stressful situation, they may be described as calm or composed. On the contrary, someone who is nervous or anxious in the same situation can be considered as an antonym for unperturbed. Likewise, if one's peace is disturbed or perturbed, the opposite of being unperturbed, they may be described as flustered or vexed. Therefore, the antonyms for unperturbed are all descriptive of someone who may be frazzled, anxious, worried or troubled.