The phrase "a proven entity" is correct and usable in written English.
It can be used to describe something or someone that has been tested and shown to be reliable or effective.
Example: "The company has established itself as a proven entity in the renewable energy sector, consistently delivering innovative solutions."
Alternatives: "a verified entity" or "a trusted entity."
"He's not a proven entity in my book," she said.
Yet 188 major league home runs later, he is not only a Met again but a proven entity.
Not that Porter will see it that way – he's now a proven entity at producing teams and combinations of players that add up to considerably more than the sum of their parts.
"She's a proven entity in extreme environments," Johnson said.
Part of the reason is that Van Liew is a proven entity, a veteran of the last edition of the quadrennial race, while the others are first-time hopefuls.
Stamford Hospital initiated CT screening for lung cancer last year "because, even though it's not a proven entity, lung cancer is often diagnosed in Stage 3 or 4 when surgery is not an option and outcomes are not as good," Ms. Manfredo said.
"We are the proven entity.
We see time and again how these people can get and sustain jobs, and once they're given a shot their behavioral issues go away". At that point, the participants become proven entities who can more easily find other jobs in the community.
They are proven entities, seasoned teachers and scholars, and they're less expensive than senior professors.
In a place like Machu Picchu, which is swarming with visitors lost in a frantic orgy of photo taking, the appearance of a novel entity proves too much to resist.
Some fictitious entities are necessary for human discourse, but their meaning can only be revealed through their connection to real entities (1977, 495n; 287 88 287–88, 317 18); if a fictitious entity proves impervious to this paraphrastic technique it is shown to be a meaningless abstraction unrelated to demonstrable reality.
