A "gut feeling" is an intuitive sense or instinctive response that doesn't rely on logic or reasoning. This phrase can also be referred to as a "hunch", "premonition", or "sixth sense". It's a sensation that's difficult to explain, but that arises from a deep-seated feeling within the core of one's being. Other possible synonyms for "gut feeling" include "instinct", "intuition", "gut reaction", "inner voice", and "spidey sense". Whether you call it a "gut feeling" or something else entirely, this sense can often be relied upon as an invaluable guide when making critical decisions about one's life or other important matters.