1
general::
Phrase(s): beef something up
to add strength or substance to something. • Let’s beef this music up with a little more on the drums. • They beefed up the offer with another thousand dollars.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Strengthen, reinforce, as in Mary wants us to beef up her part in the play. This phrase relies on an older slang sense of beef as "muscles" or "power." [Colloquial; late 1800s]
American Heritage Idioms