More specifically, a South Central Los Angeles slang terminology for a $100 bill. Popularized by west coast rap artist DrakeO The Ruler
"Try me? Please, you don't have enough uchies
Let alone enough groupies, I'm ridin with the broskis
Tell me how you wanna do it, killas ride to my music On God I can't think straight, a buck fifty on the E-way" -- DrakeO the Ruler "Uchies" (song) lyrics (2017)
This is when an individual exhibits irritability for a rational reason, but is unable to convey that their “aggression” is warranted to those in the vicinity, so it goes “unchecked”.
Someone with unchecked aggression is not necessarily dangerous, just misunderstood in the moment.
*man on street yelling and throwing fits in air from frustration due to a problem at work or home*