• perturb •
Pronunciation: pêr-têrb • Hear it!
Part of Speech: Verb, transitive
Meaning: 1. To make someone anxious or unsettled. 2. (Physics & Astronomy) To disturb a system or process, to cause it to deviate from its normal path or direction.
Notes: So, what is the difference between perturb and disturb? When referring to people or animals, perturb means "to disturb slightly". However, the physical and astronomical sense may be used figuratively, so that it is possible that perturb becomes a synonym of disturb. I would recommend that we keep the two senses separate. The noun is perturbation, the adjective, perturbative. Speakers have 'back-derived' perturbate from perturbation, and this verb has produced its own family of derivations. Unless you need the extra syllables, why not stick to the original verb: perturb.
In Play: We often hear this word modified by mildly, slightly, etc. for the obvious reason: "The office was mildly perturbed that parking meters were installed in the parking lot on the day raises for everyone were announced." Remember this word means only mildly disturbed: "Mama was perturbed having to clean up the living room all alone."
Word History: In Middle English today's Good word was perturben from Old French perturber, which French inherited from Latin perturbare. The Latin verb is composed of per "through, thoroughly" + turbare "to throw into disorder". This verb is based on turba "confusion" akin to Greek turbe "turmoil". Latin and Greek inherited their words from PIE tuer- "to turn, whirl, wind", which found its way into German as Turm "tower", apparently from their original winding stairs. Per came from what was an adverb or a preposition in PIE, for it turns up as for in English, peri "around" in Greek, and per "through" in Latin. English borrowed the last as per "by (means of), through, according to".