Trouble
Middle English: from Old French truble (noun), trubler (verb), based on Latin turbidus (see turbid).
wiktionary
Verb is from Middle English troublen, trublen, turblen, troblen, borrowed from Old French troubler, trobler, trubler, metathetic variants of tourbler, torbler, turbler, from Vulgar Latin *turbulō, from Latin turbula(“disorderly group, a little crowd or people”), diminutive of turba(“stir; crowd”). The noun is from Middle English truble, troble, from Old French troble, from the verb.
etymonline
trouble (v.)
c. 1200, from Old French trubler, metathesis of turbler, torbler "to trouble, disturb; make cloudy, stir up, mix" (11c.), from Vulgar Latin *turbulare, from Late Latin turbidare "to trouble, make turbid," from Latin turbidus (see turbid). Related: Troubled; troubling.
trouble (n.)
c. 1200, "agitation of the mind, emotional turmoil," from Old French truble, torble "trouble, disturbance" (12c.), from trubler/torbler (see trouble (v.)). From early 15c. as "a concern, a cause for worry;" 1590s as "something that causes trouble." Meaning "unpleasant relations with the authorities" is from 1550s. Related: Troubles (1510s). Trouble and strife as rhyming slang for "wife" is recorded from 1908.
