Definitions[]
Contract law[]
An unenforceable contract or transaction is one that is valid, but which the court will not enforce.
U.S. patent law[]
"A patent is unenforceable (cannot be used for the basis of a lawsuit) if the patent owner has taken some action that is considered to be in bad faith. For example, if the patent owner lied to the USPTO in order to have his patent issued, those lies may be grounds for the patent to be held unenforceable."[1]