Synonyms for Flesh Out (same or very similar meaning)
WordNet sense 1 (make fat or plump):
fat, fatten, plump, plump out, fill out, fatten out, fatten upWordNet sense 2 (add details, as to an account or idea; clarify the meaning of and discourse in a learned way, usually in writing):
dilate, elaborate, enlarge, expand, expatiate, expound, lucubrate, exposit, elaborateWordNet sense 3 (become round, plump, or shapely):
roundFrom the ODE community, based on WordNetadd/edit