What is Runty?
1.
Using agression to gain respect and/or fear from one's peers; a defense mechanism employed due to insecurity.
It's the same principle by which the runt of a litter of pups will sometimes become a biter because they don't know a better way to secure their food and/or place in the pack.
She's being a runty
bitch today. She thinks that makes her athug , but it don't.
2.
spunky, feisty, wriggly. Aka runticular.
As runty as a retriever.