adj

• Wild; untamed.
  "In this region, the wild boars can be dangerous, but (perhaps counterintuitively) the feral hogs can be even worse."
• Wild; untamed.
  "This consideration doth afford us no small light in conceiving and judging the manners and qualifications of persons, as hath been observed, that those that have impressions of grapes, or signals of vines on their bodies, are addicted to drunkenness, those who have resemblance on their bodies, or in their countenances of a boar, or any feral creature, participate in the same feral, wild and unmannerly deportment; those having any similitude of a hare, are fearful; of a fox, are cunning; of a wolf, cruel; and so of all other resemblances: and, as from these resemblances, the manners are conjectured, so likewise future events, and fortune good or bad, as shall be noted in due place. Nature is strange in many of her operations; but this is most certain, the party retains the qualities of that animal or thing to which he hath a resemblance."
• Wild; untamed.
  "Miners fans have been going absolutely feral over you, [and] you're also disgustingly talented. People want you to play for them! You had Canadians bitching about you being American born the first time you played for Team USA."
• Wild; untamed.
  "Ooh cool, I also have a feral wolf fursona!"

noun

• (Australia, colloquial) A contemptible young person, a lout, a person who behaves wildly.
• (Australia, colloquial) A person who has isolated themselves from the outside world; one living an alternative lifestyle.
  "The intolerance which was directed towards us during the early years has now shifted to ‘the ferals’ who embrace a new version of nonconformist behaviour that even some of us in their parent′s generation — the Aquarian settlers — don′t like. The ferals are the scapegoats for the drug problems here, and are highly visible since many of them have nowhere to live."
• (furry fandom) A furry character in art or literature which has the appearance of a regular animal (typically quadrupedal), that may or may not be able to communicate with humans or "anthros".
  "The story is about a group of ferals which have to explore the ruins of society after the humans die out."