Here is the Spout Lore move and some commentary on it (pp 21, 66 of my DW pdf):
Some moves . . . Give you a chance to say something about your character and their history. When you spout lore you may get asked how you know the information that the GM reveals. Take that opportunity to contribute to the game and show who your character really is. Just keep in mind the established facts and don’t contradict anything that’s already been described.
. . .
Spout Lore
When you consult your accumulated knowledge about something, roll+Int. ✴On a 10+, the GM will tell you something interesting and useful about the subject relevant to your situation. ✴On a 7–9, the GM will only tell you something interesting—it’s on you to make it useful. The GM might ask you “How do you know this?” Tell them the truth, now.
You spout lore any time you want to search your memory for knowledge or facts about something. . . .
On a miss the GM’s move will often involve the time you take thinking. Maybe you miss that goblin moving around behind you, or the tripwire across the hallway. It’s also a great chance to reveal an unwelcome truth.
Just in case it isn’t clear: the answers are always true, even if the GM had to make them up on the spot. Always say what honesty demands.