Honestly? Sounds like Defy Danger, or defend maybe? Could be H&S too, though.
What's confusing to me is the GM is leading with the fiction, not the PC.
I can't think of what move in particular you're making as a GM right there. You're probably announcing impending doom or something like that but it comes of as: the NPC makes an Attack, roll to Parry. Which you can't do in DW.
Moreover, I don't know why you're making that move in the first place. Did the PC miss? Did they just stare at you blankly?
Usually, I let the PC initiate battles, unless they hesitate or deliberately wait for the Monsters to attack, in which case I make a Monster Move or just deal Damage directly.
Like the other week the Pally burst in on a pirate's den and then demanded that they surrender peacefully or die. So, they shot him with a blunderbuss and did their damage. No roll needed on the part of the Pally. I suppose if he had said, 'Can I leap out of the way?' I'd either be like: 'In full-plate? Fuck no.' or, 'Sure, Defy Damage!'