broaden in WordNet English dictionary

1. vary in order to spread risk or to expand
   "The company diversified"
   diversify  branch out  broaden 
   
2. become broader
   "The road broadened"
   broaden 
   
3. make broader
   "broaden the road"
   broaden 
   
4. extend in scope or range or area
   "The law was extended to all citizens"; "widen the range of applications"; "broaden your horizon"; "Extend your backyard"
   widen  broaden  extend