Wiktionary
n. (context idiomatic English) An instantaneous reaction made without thought
Usage examples of "gut reaction".
The deaths had striking similarities and differences, but a crawling down his spine told him that his gut reaction believed more in the similarities than in the differences.
I don't have a personal grudge against them, I just have a real gut reaction when I see somebody running totally on rep and getting somebody else fuckin' killed, Dek, and sending mis program down the out-chute.
Average people didn't analyze what they thought: they thought they thought, and half of it was gut reaction.
Briefly he outlined to the lawyer the situation insofar as he understood it, and asked Hirsshorn what his initial and instinctive gut reaction was.
I'd only give you a gut reaction, not a considered political option.
The computer was guided by psychiatric profiles and performance analyses to the same instant decision a human director would have made by gut reaction: Lacey's mastoid implant rang him to alert.
At the gut reaction he'd had feeling like he was being unfaithful to Dia.