Wiktionary
gut feeling
n. (context idiomatic English) an instinct or intuition; an immediate or basic feeling or reaction without a logical rationale
Usage examples of "gut feeling".
She had to go with her gut feeling here, because it wasn't allowing room for anything else.
Same gut feeling for how rocks move same thing that makes a good numbers man or keeps a Shepherd out of the Well, that's what they want.
His gut feeling was to flee before it, but he knew that would be a vain manoeuvre.