Merriam-Webster Collegiate Dictionary - disperse

 verb  (~d; dispersing)  Etymology: Middle English, from Latin dispersus, past participle of dispergere to scatter, from dis- + spargere to scatter — more at spark  Date: 14th century  transitive verb  1.  a. to cause to break up police ~d the crowd  b. to cause to become spread widely  c. to cause to evaporate or vanish sunlight dispersing the mist  2. to spread or distribute from a fixed or constant source: as  a. archaic disseminate  b. to subject (as light) to dispersion  c. to distribute (as fine particles) more or less evenly throughout a medium  intransitive verb  1. to break up in random fashion the crowd ~d on request  2.  a. to become ~d  b. dissipate, vanish the fog ~d toward morning  Synonyms: see scatter  • ~dly adverb  • ~r noun  • dispersible adjective