/ɪn'væljʊəbl; ɪn`væljuəbl/
adj ~ (to sb/sth) of value too high to be measured; extremely valuable 价值高得无法估量的; 极宝贵的
*an invaluable collection of paintings 珍品画的收藏
* invaluable help, advice, etc 宝贵的帮助、意见等
* Your help has been invaluable to us. 你对我们的帮助是非常宝贵的.

NOTE ON USAGE 用法
*A few adjectives have misleading `negative' affixes such as in- or -less. 有几个形容词带有貌似｀否定＇的词缀, 如in-或-less.
1 Invaluable means `extremely valuable'. *invaluable意思是｀极有价值的＇. It is not the opposite of valuable, which is valueless (or worthless). 这个词并不是valuable的反义词, valuable的反义词是valueless（或worthless）.
2 Priceless means `too valuable to be priced', ie `having a very high price'.*priceless意思是｀贵重得无法定出价格的＇, 即｀价格非常高的＇.
3 Innumerable and numberless mean `too many to be counted' or `very numerous'. *innumerable和numberless 意思是｀多得数不清的＇或｀极多的＇.
4 Flammable and inflammable have the same meaning (opposite
*non-flammable). *flammable和inflammable意思一样, 是｀易燃的＇（反义词是
*non-flammable｀不易燃的＇）.

adj
extremely useful
invaluable to/for
　Your advice has been invaluable to us.
invaluable in/for (doing) sth
　This help was invaluable in focusing my ideas.
　The internet is an invaluable source of information.