Green’s Dictionary of Slang

big deal v.

[big deal n.]
(US)

1. to get what one wants by clever, forceful negotiation; thus big-dealing n.

[US]R.M. Lindner Stone Walls and Men 46: When you sell a stock now, no sales-talk, no promotion, no big-dealing.
[US]G. McMillan Old Breed 241: One man or combination of men in the tent had Big Dealed the components of coffee: one might have ‘borrowed’ the canned, condensed milk, another the sugar.
Snowest [Internet] My son-in-law ran into another fella with the exact same year and model sled and big dealed the owner into letting him ride it to see if there was any difference.
Drag Racing List [Internet] Wells, McCloskey, and I were running fuel in the Flathead, and tech told us we had to have a fire suit. I was in the Navy and went to the parachute loft and ‘big dealed’ a fire suit (like they fight airplane fires with).

2. to aggrandize, to magnify the importance of.

[US]T.I. Rubin Sweet Daddy 136: Doc this here call-girl stuff [is] mostly big-dealed up by the newspapers.
Former Adventist fellowship Online [Internet] I have sorta ‘big dealed’ the dress issue with my son. NOT from religious reasons either!!!
militarylifestyle.com [Internet] Persons I know who retired and somehow ‘big-dealed’ a disability are just trying to milk the system.