round out

round out (third-person singular simple present rounds out, present participle rounding out, simple past and past participle rounded out)

1. (intransitive) to become rounder, plumper
2. (transitive) To make more complete by adding details.

   Here are some actual figures to round out the basic report.

   • 2012 April 29, Nathan Rabin, “TV: Review: THE SIMPSONS (CLASSIC): “Treehouse of Horror III” (season 4, episode 5; originally aired 10/29/1992)”, in (Please provide the book title or journal name)‎:

     Mr. Burns is similarly perfectly cast as a heartless capitalist willing to do anything for a quick buck, even if it means endangering the lives of those around him and Marge elegantly rounds out the main cast as a good, pure-hearted and overly indulgent woman who sees the big, good heart (literally and metaphorically) of a monstrous man-brute.