lamb weston rule
Lamb-Weston rule. Insurance. The doctrine that, when two insurance policies provide coverage for a loss, and each of them contains an other-insurance clause — creating a conflict in the order or apportionment of coverage — both of the other-insurance clauses will be disregarded and liability will be prorated between the insurers. Lamb-Weston, Inc. v. Oregon Auto. Ins. Co., 341 P.2d 110 (Or. 1959). [Cases: Insurance 2112, 2762. C.J.S. Insurance § 1140.]