The phrase is the brothers' take on the Yiddish word mensch, an upright man, someone of substance and decency.
Would the Coens' qualify as serious men themselves?
"I don't think either of us would," Ethan Coen, 52, said in an interview alongside his 54-year-old brother at the Toronto International Film Festival, where "A Serious Man" played ahead of its theatrical release Friday.
"I don't know," Ethan continued. "It's just, you know, the weakness for fart jokes and the like."
People in Hollywood would differ. In their early years, the Coens were taken seriously by critics and the growing cult of fans they gained from such oddball films as the crime stories "Blood Simple" and "Miller's Crossing," the baby-snatching comedy "Raising Arizona" and the dark Hollywood tale "Barton Fink."
The commercial and critical success of their kidnapping-murder story "Fargo," the roots-music romp "O Brother, Where Art Thou?" and their Academy Awards champ, the crime thriller "No Country for Old Men," have established the Coens as very serious men, people of consequence, in Hollywood.
Able to do pretty much whatever they like at this point, the Coens chose to explore a familiar setting, a Midwest Jewish community in the late 1960s, a time and place akin to their own Minnesota upbringing.
With a cast dominated by local newcomers and stage actors generally unfamiliar to film audiences, "A Serious Man" tells the story of physics professor Larry Gopnik (the Tony Award-nominated Michael Stuhlbarg) enduring his own trials-of-Job hardships as his home and academic lives unravel.
The Coens' parents were college professors, but the characters and events are fictional, not a semi-autobiographical portrait of the brothers' youth.
"We knew the Midwest sort of Jewish community setting. Our mother was a very observant Jew, and we knew the academic world from our parents," Joel Coen said. "But the events in the story were made up. Our parents, their relationship and their story didn't have anything to do with this family."
The story is not exactly the stuff of a Hollywood blockbuster, even by the standards of the Coens - who followed their directing, writing and best-picture Oscar wins on "No Country for Old Men" with last year's George Clooney-Brad Pitt caper "Burn After Reading."
"We really knew that nobody was going to see this, because it's enough that you're doing a movie about Jews," said Richard Kind, the "Spin City" co-star who is one of the few well-known faces in "A Serious Man," playing Gopnik's freeloading brother.
"And then they say, `We're going to have no famous people in it. No stars.' It's really just, they're laughing in the face of economics. ... What do you do when you've won an Oscar? When you have power? You do what you want to do."