operative construction. 1. The interpretation of a writing or agreement, esp. a contract, statute,

or regulation, that is being relied on by the parties, a court, or an administrative agency. 2.Patents.A working embodiment of an invention, usu. used to conceptualize the invention and how it will work rather than to create a working model. 3. The doctrine that the interpretation of a statute or regulation made by an administrative agency charged with enforcing it is entitled to judicial deference unless it is arbitrary and capricious.

[Blacks Law 8th]