- One who is engaged in speculative mining or well drilling in areas not known to be productive.
- A promoter of speculative or fraudulent business enterprises.
- A worker who participates in a wildcat strike.
- (US) Someone who drills for oil speculatively
- A worker who participates in a wildcat strike
- (firearms) person who makes wildcat ammunition and the guns that use them.
- Roy Weatherby began his career in the firearms industry as a “wildcatter", developing his revolutionary ideas about rifle cartridge performance and design.