other insurance clause指另保条款或他保条款。

另保条款或他保条款是保险单中的一项条件条款，不允许被保险人未经保险人同意就同一承保风险另行投保。此条款通常见于火灾保险单中。如果被保险人就其财产另有保险，他应将此事实向保险人披露，并在保单上背书注明，否则该保险被视作无效。

其英文释义如下，供参考：

Other Insurance Clause — a provision found in both property and liability insurance policies establishing how loss is to be apportioned among insurers when more than one policy covers the same loss.

Excess Other Insurance Clause则为溢额他保条款，属于他保条款的一种类型。他保条款主要有三种类型：

1. 比例分摊条款（Pro Rata Clause）

比例分摊条款，即规定某一损失发生时，若该损失有其他保险合同承保，本保险（Primary Insurance）合同的保险人（以下简称本保险人）仅按照本保险人承保的保险金额与全部保险人所承保的保险金额总和的比例对该损失或责任分担保险赔偿责任的他保条款。比例分摊条款是保险人根据每一保险人保单的责任限额占所有可获赔保单的责任限额总和的比例在所有保险人之间分配保险责任的一种他保条款。The first is a "pro rata" provision that limits an insurer’s liability to the total proportion that its policy limits bear to the total coverage available to the insured. For example, if there are two policies, each with a $1 million limit, and there was a $500,000 loss, each policy would be responsible for $250,000 or 50 percent of the loss.

2. 免责条款（Escape Clause）

免责条款就是约定当某一损失发生，若该损失另有其他有效保险合同承保时，那么订有免责条款的保险人对该损失不负保险赔偿责任的他保条款。免责条款的一个典型表述为：如果本保单保障的被保险人根据保单条款有权获得赔偿，但同时也受其他有效的可获赔的（Valid and collectible）保险保障，那么，该被保险人将根据本保单不能获得赔偿。The second  is an "escape" provision that extinguishes the insurer’s liability if the loss is covered by the other insurance. In that case, even if the loss were $1.5 million, the insurer with the "escape" provision would pay nothing, and the other insurer would pay its full limits. The interplay between these "other insurance clauses" can be critical when determining priority of coverage.

3. 溢额他保条款（Excess Other Insurance Clause）

溢额责任条款，与主要保险条款（Primary Insurance Clause）相对，即如果主要保险人（Primary Insurer）在对某一损失或责任承担全部保险赔偿责任后，溢额责任条款的保险人（Excess Insurer）的保险赔偿责任仅限于对超过主要保险人的保险金额总和的损失部分承担赔偿责任的他保条款。也就是说，订立溢额责任条款的保险人只在主要保险人用尽保险金额后才对剩余的损失予以赔偿。溢额责任条款的保险人承担的是其他保险人（主要保险人）赔付后的补充责任。如果溢额责任条款的保单项下的损失存在其他保险，则该保单规定的保险将是超过所有其他有效的、可获赔保险的溢额保险。如果该保单持有人不存在主要保险，那么该溢额保险的承保人将承担主要保险责任（Primary Insurance Liability）。由于溢额责任保险只负责主要保险限额以上的损失部分，因此又称为“伞状”责任保险（Umbrella Liability Insurance）。

The third is an "excess only" provision that requires the exhaustion of the other insurance before any payments are available on the excess policy. So, using the same example, the policy with the "excess only" provision would pay nothing, and the other policy would pay the full $500,000 loss.

以下为相关双语示例，供参考：

"Other insurance" clauses in insurance policies are designed to "vary or limit the insurer's liability when additional insurance coverage can be established to cover the same loss." Where two or more insurance companies "provide concurrent coverage for the same risk at the same level," courts rely on other insurance clauses to determine if, and how, the insurance companies will share in coverage.

保单中的“他保”条款旨在于存在其他保险可以覆盖同一损失时”变更或限制保险人的责任。当两家或多家保险公司同时为同一风险提供同一水平的保额时，法庭一般会依赖他保条款确定保险公司是否以及如何分担保险赔偿。