endeavour竭力，尽力，既可以作名词，也可以作动词，因此合同中常见的表达有两种：endeavour to, use reasonable/all/best endeavour to，类似的表示尽力做某事的表达还有make one's best efforts to, to the best of its ability等，在合同中都比较常见。

endeavour to

Without prejudice to Clause 03.4, each of the Restricted Persons undertakes with the Buyer for itself and each Group Company that it will not in any Relevant Capacity, during the Restriction Period and within the Restricted Area, in competition with the Relevant Business operated by any Group Company solicit, canvass or persuade orendeavour to solicit, canvass or approach any customer or client of a Group Company in the Restricted Area.

在不影响第03.4条规定的前提下，各位受限人士为其自身和各集团公司向买方承诺，其不会以任何相关身份：在限制期间和受限区域内，与任何集团公司经营的相关业务竞争，招揽、游说或者鼓励、或者争取招揽、游说或者获取集团公司在受限区域的任何顾客或客户；

use reasonable/all/best endeavour to

If prior to the Due Date, the Buyer has served on the Sellers’ Representative in good faith a Notice of Claim with respect to an Agreement Claim and the Notified Claim has not yet become a Settled Claim, the Buyer shall use reasonable endeavours to quantify the maximum amount of the Notified Claim and shall notify the Sellers in writing of the estimated amount of the Notified Claim together with the reasonable evidence supporting the estimated amount of the Notified Claim .

如果在到期日之前，买方已经向卖方代表善意送达一份索赔通知，该通知关于协议索赔且该等已通知的索赔尚不是已决索赔，则买方应当尽其合理努力确定已通知的索赔的最高金额并且将已通知的索赔的预计金额和支持已通知的索赔预计金额的合理证据书面通知卖方。