Writ large is a phrase meaning obvious or clear.
Writ is an archaic form of ‘written’. So one can understand the idiom writ large as something written largely or magnified. However, it should always be in reference to a specific noun, used after said noun as an appositive, and not as a verbal phrase (e.g., is writ large). It does not require the use of commas. Can also be used in the forms writ larger and writ largest.
Another phrase is writ small, which is used similarly to writ large and has an opposite meaning.
Examples
Waleed Aly was right to remind us that while there may be important wins, challenges and losses in the courts, refugee policy writ large has neither been reset nor altered. [Guardian]
There seemed to be a great relief writ large as the locals tried to stock up on essentials. [Indian Republic]
This year’s Man Booker Prize, in its first outing since the controversial rule change, was widely tipped to be The Coming of the Americans writ large. [Global Comment]
You might say Third Man is White’s former Detroit world writ large — a bigger version of the old shop where his upholstery work mingled with music, art and creative brainstorming. [Detroit Free Press]
The competition doesn’t lack for drama. It’s writ small, though, like in a home kitchen (with the exception of Iain Watters’s BakedAlaskaGate). [The Washington Post]
It’s The Godfather writ small, even written on the top of a baseball bat. [Financial Times]