To Burst Out
To Spout Out, To Spray Out
intransitive verb, godan verb
噴 means eruption, and 出す can mean "to let out," right? Well if you let out an eruption, it's probably going to cause something to burst out. You know, like lava out of a volcano. Or maybe it's going to to spout out, like a geyser out of the earth.
This may remind you of another word you've learned: 吹き出す. They're very similar and often interchangeable, but in general 噴き出す is used for things that spout out with even more power and intensity. Along those lines, it can also be used figuratively, like when pent-up emotions burst out suddenly.
Remember how you learned the word 吹き出す? Well, this is read the exact same way and means almost the exact same thing. If you know one reading, you know both!
今までためていた怒りが一気に噴き出した。
The anger that had built up burst out at once.