It’s a woman ( or man ) under 18 who is not fully developed in the chest area.
A slang term used commonly by yutes in the UK in order to define something that is very insignificant / small.
Person 1: Ffs I just lost £1 on the bus!
Person 2: Minor, it’s only £1
Minor = Not worrying
Random guy-Aye bro didn't you get cuffed last week, why you back to doing the stupid shit again
Me-Minor
a new form of sex doll invented by the Gooning Republic of danny deVito
That Minor has a giant penis, is it futa??