Yeah, you won't find our meaning in a dictionary, cos it's a colloquialism.
In Australia, Feral also means invasive species, and pest
Feral cats are a big problem here, because they kill a lot of the smaller wildelife that previously had no similar predators, and so they haven't evolved to defend against them.
Feral rabbits are a pest. Feral cane toads are a pest. Feral people are a pest, and are likely to try to steal your car or the washing off your line.
It also means something a bit yuck.
My hair was a bit feral this morning, cos I hadn't washed it for a week.
The English language is a wacky thing, and ends up with a lot of variations, depending on the country it's used in.
