翻译后大致有三个意思，具体如下：
1.错误地例句：He opened Ingrid''s letter by mistake.;他不小心拆了英格丽德的信。
2.由疏忽所致例句：She let the news slip by mistake, in an unguarded moment.;她一不留神泄漏了消息。
3.错拿某物例句：She sprayed hair spray in her eye by mistake.她错把洗头水当成眼药水上到眼睛里了。
by himself：通过他自己,用于主语是HE（他自己）时。
by him：通过他,用于主语不是他自己时。
例如：he did it himself表示他亲自做这件事。
he did it by himself表示他单独一个人做这件事的。
1.He will by no means give up his love.他决不会放弃他的爱。
2.By no means can the dream come true.这个梦想决不会成真。
3.I am by no means an unsociable person.我绝对不是一个不合群的人。
4.His view is by no means without foundation.他这种看法决不是凭空产生的。
5.He was forceful,but by no means a zealot.他个性坚定，但绝不是什么狂热分子。
6.The occurrence of such things is by no means fortuitous.出现这种问题绝不是偶然的。
7.The problem is by no means as simple as we first thought.问题决不像我们当初想象的那么单纯。