A piece of Aussie lore that evolved into slang becomes the title of “Buckley’s Chance,” a lad-lost-in-the-Outback drama that takes a bloody long time to get that lad lost in the Outback.

It’s about Ridley (Milan Burch), a New York city kid whose mother (Victoria Hill) drags him to Australia after his Oz-born firefighter dad dies in the line of duty. This son of a hero has become a discipline problem, so maybe a little visit with the grumpy grandad he’s never met will set him straight.

Bill Nighy plays Spencer, a grouse “trying to run a sheep station” who “doesn’t need a grieving widow” and her “pain in the arse son” around, complicating life.

But guilt over his estranged son forces old Spencer to make an effort, teach the kid a little Outback survival and outback lore — and explain why he pulls out his .30-06 and points it at dingoes every time he spies one, out mending fences and such.

“You’re gonna shoot a DOG?”

“They may look like a dog, Ridley, but they’re more wolf than dog.”

The kid isn’t convinced. So when the chance comes to rescue a fine specimen of the breed trapped in a fence, he makes a new friend. He names it after grandpa’s ranch, “Buckley’s Chance.” Buckley might come in handy when the going gets tough. Which it does, sort of, after a very long set-up.

Repeating the phrase “There’s no strength without struggle” has got to pay off eventually, right?

We sample some lovely and exotic Outback scenery — OK, dry, dusty and forbidding locations, including an abandoned open pit mine — a boy and his dog and Nighy to recommend “Buckley’s Chance.”

But the meandering story, abrupt shifts in tone and character, absurd incidents and plot twists, pauses for flashbacks and criminals who would only “play” here if they were funny let much of the air out of this.

Nighy doesn’t do much of an accent, so it’s up to Kelton Pell and other supporting players to provide the “local color.”

Still, it’s sentimental and kid-friendly, with a couple of decent grace notes. If your kids are at the undemanding age, have at it. Just try not to notice when the plot and incidents in it turn eye-rolling.

MPA Rating: unrated, animals in peril

Cast: Bill Nighy, Milan Burch, Victoria Hill, Kelton Pell

Credits: Directed by Tim Brown, script by Tim Brown and Willem Wennekers. A Vertical release.

Running time: 1:36