The race against the clock — to solve a crime, to outwit a villain, to escape one’s fate — has propelled the plotlines of dozens of the movies that define Hollywood’s golden age of noir, the dark movies that dominated screens from the 1930s to the ’50s.

“Time and film noir go together like ham and eggs,” said Alan Rode, an author and a director of the Film Noir Foundation, which sponsors Noir City, a continuing series of film festivals that this month has been scheduled in Chicago, Detroit, Washington and Philadelphia. “Time is a continuum not only of our lives, but also in film noir.”

That foreboding sense of time defines film noir — in English, “dark film” — a phrase that was coined in 1938 by Lucien Rebatet, the French author who wrote under the pseudonym François Vinneuil, but is most closely associated with the French film critic Nino Frank. He used it in 1946 to define the cynical films of postwar America.

The genre itself, however, has not been defined anywhere near as clearly.

Some film scholars have said it describes detectives or private eyes caught up in a world of crooks and femme fatales who lead them astray. But a broader definition has been the immoral journey of a protagonist caught in downward spiral, all of it being clocked somehow in the shadowy black-and-white of film.

“Film noir is replete with time moments, partly because the driving mechanism of its stories is suspense, and partly because the lost chances and missed deadlines of noir lends a strong mood of regret and pathos,” Helen Hanson, an associate professor of film history at the University of Exeter in England and the author of several books on noir, said by email.

“Perhaps because film noir existed in an era defined by time and life lost during World War II, it featured a heightened sense of how quickly life can go haywire.”