Feeble

/ˈfiːbəl/
not effective; not showing determination or energy 无效的；缺乏决心的；无力的
a feeble argument/excuse/joke
无力的证据；站不住脚的借口；不好笑的笑话
a feeble attempt to explain
无力的试图解释
Don’t be so feeble! Tell her you don’t want to go.
别那么软弱了！告诉她你不想去。