pretext

The leaders used a minor clash at the border as a pretext for war. [=as a reason/excuse for starting a war]领导者们利用边界上的小冲突作为托词发动战争。

She always managed to visit him on one pretext or another. [=she found various reasons to visit him]她总设法找出各种借口去拜访他。

She went back to her friend's house on/under the pretext that she had forgotten her purse.她借口落下了手提包，又返回到朋友家里。