英語で no such thing とはどういう意味ですか

mattchandkdkdさん

There is no such thing as XXXX といった形で使われます。
XXXX などない（この世に存在しない）。

一例として、【There's No Such Thing As A Free Lunch】
直訳すると（無料の昼食などない。）があります。
意味は、
The economic theory, and also the lay opinion, that whatever goods and services are provided, they must be paid for by someone - i.e. you don't get something for nothing.【The Phrase Finderより】
A person or a society cannot get something for nothing. Even if something appears to be free, there is always a cost to the person or to society as a whole even though that cost may be hidden or distributed.【wikipediaより】
If someone gives you something, they always expect you to give them something or to do something for them.【The Free Dictionary ｂｙ Fardexより】
だそうです。（"There Ain't No Such Thing As A Free Lunch", TANSTAAFL）とも言うようです。