[Spoilers] What does the title "Oathbreaker" mean?

I think this might be some sort of misdirection on the developing Riverrun plot and involves Jaime. We have seen shots of either Riverrun or The Twins as some sort of hint at a Red Wedding 2.0 and there were Lannisters there. We also know from speculation and filming leaks that there will be a siege at Riverrun so perhaps this episode is where that starts to be set up and play out and Jaime is now the "Oathbreaker" because he's aggressively leading the Lannisters in taking Riverrun which most definitely would be going against the woman he made an oath to.

I know it doesn't relate to the oath he made to her about Sansa so the only other thing I can think of is that Brienne shows up there this episode and the two of them have to make a collective decision since they are on opposite sides of the battle considering Brienne most likely just left Sansa's side to come to Riverrun in search of Arya.

There has to be some sort of 'turning point' for them that parallels the books and since there's no LSH that we know of still ... this plot is changing quite a bit in s6 for sure.

Is the siege of Riverrun an elaborate ruse to get Walder and his enormous pack of Freys inside Riverrun to pull the trick of RW 2.0? Are they setting it up in episode 3 that Jaime is the "Oathbreaker" who then does a trick like his Father and switches sides at the end?

I think it relates to Jaime. I wonder if this is the episode where Cersei proposes that Jaime go to Riverrun? He swore an oath to protect the Stark girls, and going against the Tully family certainly is about as opposite as you can get at the moment.

This has been a popular vote over in the speculation thread and it very well could be if what we think is going to happen happens in this episode ... but really "Oathbreaker" is far more blatantly referring to Jaime and Brienne's oaths to Catelyn. But again, they're known for being weird with the episode titles for trickery and misdirection! 

Well, I don't think it really applies to Jon as his watch ends with his death. Not his fault he came back to life.

I'm wondering if Jaime finding out Sansa is with the Boltons could play into this as well? He didn't know about that before he left for Dorne. He might feel as if he's deliberately sabotaging Cersei as he sent Brienne after Sansa, and he knows Brienne will eventually figure out where she is.

Jaime doesn't go to the Riverlands until ep. 607. He's in KL as late in the season as ep. 606. Brienne gets to Riverrun a bit after him, so presumably she only arrives in the Riverlands in the first place in the midseason. And we know the Riverrun set was only used for two episodes which are either 607 and 608 or 607 and 609. Now the title could allude to them in different ways, I guess, but their reunion is a long way off still by ep. 603.

I imagine it still does refer to Jaime in part but in a different context since his early arc will be about Tommen, the Tyrells and the Faith. And in part to Jon as well since I think this is the episode he's resurrected in. It could be some people in the NW other than him are deemed Oathbreakers in that very episode and executed.

Well it's about time you and @alcasinoroyale showed up to tag team this topic! 

I think a lot of us are not quite as clear on the timeline for certain with known information. Why is it again we know for certain Jaime is in KL for 6x06? The episodes were meta-tagged /  labeled on EW or somewhere's site?

Ah see my memory is bad on that now from before I left for awhile. I thought the 6x06 clapper was from Arya's scenes for some reason. I better go back and re-read that long known-info thread AGAIN!

Count me in among those who think it refers to Jon. Maybe he resurrects in 6x02 and shows the finger to the Night's Watch in 6x03.