an exploratory oil well drilled in land not known to be an oil field
"The company decided to drill a wildcat despite the high risk, hoping to strike oil where no previous surveys had shown any potential."
any small or medium-sized cat resembling the domestic cat and living in the wild
"The researchers tracked a rare wildcat wandering through the dense forests of the Andes mountains."
A cat that lives in the wilderness, specifically
"The hikers were surprised to see a wildcat prowling near the edge of the forest while they were camping alone."
Felis silvestris, a common small Old World wild cat somewhat larger than a house cat.
"The local wildlife biologist spent hours tracking the elusive wildcat through the dense underbrush of the forest reserve."
To drill for oil in an area where no oil has been found before.
"The energy company decided to wildcat a new site despite having zero prior geological data to suggest oil was present there."
outside the bounds of legitimate or ethical business practices
"wildcat currency issued by irresponsible banks"
"wildcat stock speculation"
"a wildcat airline"
"wildcat life insurance schemes"
without official authorization
"an unauthorized strike"
"wildcat work stoppage"
(of a mine or oil well) drilled speculatively in an area not known to be productive
"drilling there would be strictly a wildcat operation"
"a wildcat mine"
"wildcat drilling"
"wildcat wells"
Of or concerning businesses operating outside standard or legitimate practice, especially:
"The startup faced a sudden shutdown after regulators shut down its wildcat operations that bypassed all safety inspections and environmental laws."
Of or concerning irresponsible banks or banking, (particularly) small, independent operations.
"The state regulator warned that if these wildcat banks continue to operate without oversight, they could destabilize the entire local financial system."
The word wildcat comes from Middle English, combining the words for wild and cat. Its original meaning referred to the actual animal, while later adjectival uses originated in America around 1837.