round (v)
flesh out (v)
fill out (v)

Definition: become round, plump, or shapely
Example: The young woman is fleshing out.

fat (v)
fatten (v)
fatten out (v)
fatten up (v)
fill out (v)
flesh out (v)
plump (v)
plump out (v)

Definition: make fat or plump
Example: We will plump out that poor starving child.

dilate (v)
elaborate (v)
enlarge (v)
expand (v)
expatiate (v)
exposit (v)
expound (v)
flesh out (v)
lucubrate (v)

Definition: add details, as to an account or idea
Example: She elaborated on the main ideas in her dissertation.