Nolo's Plain-English Law Dictionary

Doctrine Of Equivalents

A form of patent infringement that occurs when an invention performs substantially the same function in substantially the same manner and obtains the same result as a patented invention. As a result of a Supreme Court decision, the doctrine of equivalents must be applied on an element-by-element basis to the patent claims. (See also: patent claims)
NOLO-web3:DRU1.6.8.27.20160921.41205