Definition
A significant accomplishment or feat that is not easy to achieve.
一项卓越的成就或壮举，并非易事。
Completing this complex project in such a short time is no mean achievement.
在如此短的时间内完成这个复杂的项目，这绝非易事。
It is no mean feat for him to win this award at such a young age.
他在如此年轻的年纪就赢得这个奖项，这绝非易事。
Successfully organizing this event without any external help was no mean achievement.
在没有任何外部帮助的情况下成功组织这次活动，这绝非易事。