If you are helpless, you do not have the strength or power to do anything useful or to control or protect yourself.
例句
Parents often feel helpless, knowing that all the cuddles in the world won't stop the tears...父母经常感到无能为力,因为他们知道无论多少次拥抱也无法止住眼泪。Children are dying, and I am helpless to do anything...孩子们已奄奄一息,而我却无力做任何事情。
英汉词典释义
adj.
无助的, 无保护的
They felt helpless to do anything about it.他们对这事感到无能为力。