a. 1. Unsound; worthless; irresponsible; unsafe; -- said to have been originally applied to the notes of an insolvent bank in Michigan upon which there was the figure of a panther. [ 1913 Webster ]
2. (Railroad) Running without control; running along the line without a train; as, a wild-cat locomotive. [ 1913 Webster ]
(adj) outside the bounds of legitimate or ethical business practices, Example:wildcat currency issued by irresponsible banks; wildcat stock speculation; a wildcat airline; wildcat life insurance schemes
(adj) (of a mine or oil well) drilled speculatively in an area not known to be productive, Example:drilling there would be strictly a wildcat operation; a wildcat mine; wildcat drilling; wildcat wells