conglomerate

Adjective

• composed of heterogeneous elements gathered into a mass
  • the conglomerate peoples of New England
    

Noun

• a group of diverse companies under common ownership and run as a single organization

• a composite rock made up of particles of varying size

Verb

• collect or gather
  • Journals are accumulating in my office
    
  • The work keeps piling up
    

Related words

• Synonyms: 
  empire , pudding stone , accumulate , cumulate , pile up , gather , amass