round out in WordNet English dictionary

1. make bigger or better or more complete
   round out  fill out 
   
2. fill out
   "These studies round out the results of many years of research"
   round out  finish out 
   
3. make round
   "round the edges"
   round  round out  round off 
   
4. express as a round number
   "round off the amount"
   round off  round down  round out  round 
   

round out in English Wiktionary