“insecurity clause”顾名思义，不安条款。

该种合同条款出现于以下情况下：１在借款合同中，如果债权人有理由相信债务人将要违约，当债务人突然丧失重要收入来源时，则允许债权人请求债务人立即全部返还借款余额；２在动产抵押中，当抵押权人认为其抵押权不能保障时，可据此条款而有权占有抵押动产；３在票据中的一项条款，若持票人认为其票据权利是不安全的，则有权加速票据到期，从而要求提前付款。

其英文释义如下，供参考：

An "insecurity clause" is a provision in a loan agreement or promissory note that allows a lender to accelerate payment of a debt, demand additional collateral, or halt future advances if the lender has good reason to believe that the debt cannot be paid in accordance with the terms of the agreement.

与之相关的条款有acceleration clause提前到期条款；加速到期条款。

指如果约定的特定事件发生，例如未能支付分期付款的款额或未能及时缴付保费，则可以要求债务人在约定的到期日之前付清全部余额。该条款一般出现在贷款协议、抵押合同、本票、债券或信托契据中。另据美国《统一商法典》〔U.C.C.〕，如果所约定的提前到期是「任意的」，则须在根据「诚实信用」原则而相信将来偿付可能会受到损害时，才可以请求提前履行。 

以下为相关双语条款：

示例一：

INSECURITY. At any time Lender believes in good faith that the prospect of payment or performance of any of the Obligations or performance under any agreement securing the Obligations is impaired; all of the Obligations shall, at the option of Lender and without notice or demand, become immediately payable; and Lender shall have all rights and remedies for default provided by the Wisconsin Uniform Commercial Code and this Agreement, as well as any other applicable law, and under any evidence of or document relating to any Obligation, and all such rights and remedies are cumulative and may be exercised from time to time. 

不安条款。贷款人在任何时候善意认为债务的支付或为债务提供担保的任何协议项下的义务的履行将受到损害时；贷款可选择使所有债务立即到期应付，无需进行通知或要求；同时贷款人应享有《威斯康星州统一商法典》和本协议以及任何其他适用法律、与任何债务有关的证据或文件项下规定的针对违约的所有权利和救济。此类权利和救济可累积享有，并可不时行使。

示例二：

INSECURITY. Bank at any time and for any justifiable reason shall believe in good faith that the prospect of repayment of the Loans or any part thereof and Borrower’s compliance with the terms of the Loan Documents is or will be impaired.

不安条款。银行在任何时候出于任何正当理由善意认为贷款或任何部分贷款的偿还以及借款人对贷款文件之条款的遵守受到或将受到损害。