Combining them, `所获 (suǒ huò)` means “that which is gained”. `无所获 (wú suǒ huò)` means “to not have that which is gained” or “to gain nothing”. Adding `一 (yī)` at the beginning emphasizes the totality of the failure: “to gain absolutely nothing at all”.
As a `成语 (chéngyǔ)`, “一无所获” is part of a rich tradition of using concise, classical phrases in modern language. Using chengyu demonstrates a level of education and linguistic fluency. While the concept of a “fruitless effort” is universal, the Chinese expression is a compact, formal, and powerful unit. In Western culture, you might say “it was a wild goose chase,” “we came up empty,” or “it was all for naught.” These are excellent translations, but they are often more colloquial. “一无所获” carries a slightly more formal and definitive tone. It's not just that the effort was wasted; it's that the result was quantifiably zero. This reflects a cultural emphasis on results and outcomes. An effort that yields nothing is clearly and starkly described by this single, unambiguous phrase.
“一无所获” is widely used in both written and spoken Standard Chinese, though it's more common in situations where a serious effort has been made. It's not typically used for trivial matters.