“The Gentlemen” is vintage Guy Ritchie, an old-fashioned/new-fangled mob tale of the “Snatch,” “Lock, Stock and Two Smoking Barrels” Cockney comedy with lots of killing thrown in.

None of this “Aladdin” nonsense. It’s “RocknRolla” — the entertaining but weak third film in his early gangland trilogy, and most apt comparison here — all the way.

Ritchie’s rounded up a lot of folks who can act tough and handle funny — Charlie Hunnam, Eddie Marsan, even Michelle Dockery (“Downton Abbey”), with an Irishman (Colin Farrell), an American (Matthew McConaughey) and a couple of reinventions. Hugh Grant tosses aside a lifetime of forelock-tossing, stuttering, posh romantic leads and turns amusingly sinister, or attempted sinister. And Henry Golding dodges the Hugh Grant bullet by ditching the “Crazy Rich Asians/This Christmas” fey romantic lead rep for a badass turn, playing a hothead named Dry Eye.

Oh yeah, there are some screwball street names — Lord George, The Coach, Trigger, Lord Snowball, Phuc and so on.

It’s built on slang and banter — pages and pages of plot and recitative, characters telling their portion of the story, making mob gorilla threats and introducing snippets of British street-speech to the larger world.

“When the Silverback gets more ‘silver’ than ‘back, he’d best move on. Before he gets moved on.”

All that speechifying slows down the works.

“Gentlemen” takes-an-entirely too-leisurely stroll through Brexiting Britainnia and the coming Legalization of Pot (“Bush,” over there, “cup of tea,” “white widow super cheese.”

It’s a marvel to listen to. But man, is there a lot of listening to do. And listening.

The story is framed in a blackmail pitch by sniveling private eye Fletcher (Grant), a verbose and probably-gay hireling of the UK’s notoriously vindictive print press. He’s strong-arming Ray (Hunnam) a top mob lieutenant to American-born/Oxbridge educated Pot King Mickey Pearson (McConaughey).

The third-year-film-student conceit to this “pitch” is that Fletcher presents his blackmail-worthy revelations as a screenplay he’s written that he expects Ray’s boss to pay a fortune to suppress.

Student filmmakers make movies about wanting to make a movie. Not that Fletcher is all hellbent to make it. The £20 million pounds he wants to NOT make it would work, too.

Fletcher, winking and flirting (Ray may be gay, too and UNinterested — adds some frisson to their scenes) through this pitch in Ray’s tony suburban designer house.

He knows Mickey is looking to sell out his Britain-wide pot network, lays out how Mickey has circumvented Britain’s land-shortage and land-“rambling” rights nationwide — Who could hide a grow farm in all that traffic? — and how he and his “Cockney Cleopatra” (Dockery) have their price and an American “Jew” buyer (Jeremy Strong).

But the Chinese mob run by Lord George (Tom Wu) and fronted by murderously ambitious Dry Eye (Golding) want in.

And then there are the brawling, boxing rapper-wannabes of the gym run by The Coach (Farrell). They’re black.

Ritchie has cooked up a racial stew of Cockney rhyming slang, spit-out rap lyrics, racist Chinese pidgin English wisecracks and veiled anti-Semitic jokes for this story of a rushed sale in “the puff game (pot)” before “the new gold rush” begins, with pot legalized with whoever controls Mickey’s empire having the leg up on the big, new market.

Landed gentry and their heroin addict kids, a boorish, crude and vengeful newspaper editor (Marsan), movie mogul, illegal firearms, from “paper weight” size to military-grade and lots and lots of funny lines dress up a story of social or underworld insults and the mob war that spins out of that.

So much bartering — “Unlike salt and pepper, it’s not on the table.” — much of performed by McConaughey, who drawls like an American who’s picked up the “you lot” affectations of Brit-speak.

And all this lawbreaking, with nary a bobby in sight.

“In France, it’s illegal to name a pig ‘Napoleon. But try and STOP me!”

It’s all so witty and quotable, with interruptions for the old Guy Ritchie ultra-violence and dark sexual kink, with shots aimed at the British press and British aristocracy and a whole lot of “foreign” people of color being fended off by white Brits and an American transplant.

Very “now,” in other words. Ritchie papers over a paper-thin story with artificial twists and very funny turns by the likes of Farrell, Grant, Marsan and Dockery.

He gives us a lot to chew on as text, and disturbing (Racist?) subtexts. And when the movie’s forward motion is as halting as a Hugh Grant stutter, we have entirely too much time, in mid-movie, to chew on it.

MPAA Rating: R for violence, language throughout, sexual references and drug content

Cast: Matthew McConaughey, Michelle Dockery, Charlie Hunnam, Henry Golding, Colin Farrell, Eddie Marsan, Jeremy Strong and Hugh Grant

Credits: Written and directed by Guy Ritchie. An STX release.

Running time: 1:53