perturb (Verb) — Disturb in mind or make uneasy or cause to be worried or alarmed. ex. "She was rather perturbed by the news that her father was seriously ill"
perturb (Verb) — Disturb or interfere with the usual path of an electron or atom. ex. "The electrons were perturbed by the passing ion"
perturb (Verb) — Cause a celestial body to deviate from a theoretically regular orbital motion, especially as a result of interposed or extraordinary gravitational pull. ex. "The orbits of these stars were perturbed by the passings of a comet"
perturb (Verb) — Throw into great confusion or disorder. ex. "Fundamental Islamicists threaten to perturb the social order in Algeria and Egypt"