whereby: by the agreement; by the contract; by the following terms and conditions etc. 凭此协议，凭此条款等等，此词常用于合同协议书中，引出合同当事人应承担的主要合同义务。
例一
A commission contract refers to a contract between the commissioning party and the commissioned party whereby the commissioned party shall handle the business of the commissioning party.
委托合同是委托人和受托人约定，由受托人处理委托人事务的合同。（合同法第396条）
例二
A sales contract refers to a contract whereby the seller transfers the ownership of an object to the buyer and the buyer pays the price for the object.
买卖合同是出卖人转让标的物的所有权于买受人，买受人支付价款的合同。