Merriam-Webster Collegiate Dictionary - disturb

 verb  Etymology: Middle English ~en, destourben, from Anglo-French & Latin; Anglo-French destorber, from Latin ~are, from dis- + turbare to throw into disorder, from turba disorder — more at turbid  Date: 14th century  transitive verb  1.  a. to interfere with ; interrupt ~ing the flow of traffic  b. to alter the position or arrangement of the items on her desk had been ~ed  c. to upset the natural and especially the ecological balance or relations of wetlands ~ed by development  2.  a. to destroy the tranquillity or composure of the noisy lawnmower ~ed their sleep  b. to throw into disorder  c. alarm  d. to put to inconvenience sorry to ~ you at such a late hour  intransitive verb to cause ~ance  Synonyms: see discompose  • ~er noun  • ~ingly adverb