"proven entity" is correct and usable in written English.
You can use it when describing a person or organization that has achieved recognition for their success or reliability. For example, "Google is a proven entity in the tech industry, known for setting the standard for the most innovative products."
"We are the proven 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.
They are proven entities, seasoned teachers and scholars, and they're less expensive than senior professors.
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.
26 However, if this newly described entity is proven to impact on prognosis, easier ways of detecting the disease may be needed in the field.
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.
This hypothesis has subsequently been proven for some tumour entities, such as astrocytomas, glioblastomas, breast carcinomas, lung carcinomas, colon adenocarcinomas, and prostate carcinomas (Yoshioka et al, 1996; Takeda et al, 2000; Rzeski et al, 2001; Abdul and Hoosein, 2005; Ishiuchi et al, 2007).
