What it means
Means you’ve got a gripe you need to raise with someone, usually a bit awkward but not necessarily a full-blown row. Saying you have a bone to pick sets the tone: there’s something you can’t let slide, and you want answers. Often used before calling out a mate for a small betrayal or recurring annoyance.
Usage examples
"Oi, I’ve got a bone to pick with you, you nicked my posh yoghurt again. Next time, buy your own and leave mine alone, yeah?"
"I've got a bone to pick with whoever finished the milk and put the empty carton back in the fridge."
"She had a bone to pick about the rota, but said it over tea so nobody felt got at."
"I've got a bone to pick with you, mate. You said five minutes and rocked up an hour later with a coffee and no apology."
"Right, I've got a bone to pick with whoever kept pinching my charger and leaving me with 2 percent and a dream."
Where it comes from
This one’s old-school. Back in the 1500s, a bone to pick was literally a bone with scraps of meat still on it, something left unfinished. By the 1800s, English had flipped it into a grievance that still needed dealing with. Same bone, just now it’s social chewing.