wildcat

A cat that lives in the wilderness, specifically

A person who acts like a wildcat, (usually) a violent and easily-angered person or a sexually vigorous one.

An offensive formation with an unbalanced line and a snap directly to the running back rather than the quarterback.

A wheel that can be adjusted so as to revolve either with or on the shaft of a capstan.

Clipping of wildcat money, notes issued by a wildcat bank.

To drill for oil in an area where no oil has been found before.

“You'd have to be very rich or very desperate to go wildcatting that far east.”

(usually derogatory) Of or concerning businesses operating outside standard or legitimate practice, especially:

Of or concerning customized or hand-made cartridges.

Unauthorized by the proper authorities.

A cartridge modified from another calibre rather than being commercially produced.

(organized labour) A labour strike that has not been authorized by the leaders of a trade union.