1. become round, plump, or shapely
e.g. The young woman is fleshing out
2. add details, as to an account or idea
clarify the meaning of and discourse in a learned way, usually in writing
e.g. She elaborated on the main ideas in her dissertation
Synonym: elaboratelucubrateexpatiateexpositenlargeexpandexpounddilate
3. make fat or plump
e.g. We will plump out that poor starving child