flesh out in WordNet English dictionary

1. add details, as to an account or idea; clarify the meaning of and discourse in a learned way, usually in writing
   "She elaborated on the main ideas in her dissertation"
   elaborate  lucubrate  expatiate  exposit  enlarge  flesh out  expand  expound  dilate 
   
2. make fat or plump
   "We will plump out that poor starving child"
   fatten  fat  flesh out  fill out  plump  plump out  fatten out  fatten up 
   
3. become round, plump, or shapely
   "The young woman is fleshing out"
   round  flesh out  fill out 
   

flesh out in English Wiktionary