Other forms: blurts, blurted, blurting
To blurt is to say something suddenly without meaning to. The words are out before the brain catches up.
It nearly always takes out, so blurt out is really the whole verb. What gets blurted is usually a secret or something embarrassing, which is why the word is so often followed by regret. It suggests pressure released rather than a decision made, which is what separates it from simply saying. The word is informal and slightly comic, and it belongs to dialogue more than to description.
1verbblurtTo say something suddenly and without thinking.
“He blurted out the whole story before she could stop him.”
Middle English
blurden — to wail, cry out, threaten
English, today
blurt
Built from
Possibly imitative of the sound, or possibly an alteration of Middle English blurden (“to wail, cry out, threaten”), or possibly from Middle English blerten, blarten, blorten, from Old English blǣrettan, a frequentative or emphatic form of blǣran (“to blear, bellow, roar”). If so, equivalent to blear + -t.
Etymology from Wiktionary, CC BY-SA