Junior Mint is a term of endearment for the newly-minted, smart-as-a-whip, hand-raising, go-getters that are in the early stages of their careers and that no team/company/non-profit/group wants to be without. Junior Mints are rock stars and will likely PWN you one day.
Karin is hands-down the best Junior Mint I've met in Seattle!
Don't you have any Junior Mints that can whip this fuster cluck of an event into shape?
A younger man, usually well-off, who financially supports an older man (or woman) in exchange for sex and companionship. Derived from another confectionery-based term, it's the reverse of Sugar Daddy. The 'junior' refers to his youth; the mint part means money.
"I'm middle-aged, broke, and like them barely legal. I need a Junior Mint."