Gut (noun)

1. The digestive tract, especially the intestine.
2. A person's instinct or intuition.
3. The essential or innermost part of something.
4. A sense of intuition or feeling that guides a person's actions.
5. The inside or core of something.

Origin:

Middle english: probably of scandinavian origin; related to swedish gut.

Examples:

1. The food passes through the gut before being absorbed into the bloodstream.
2. She trusted her gut and took the job.
3. The gut of the building was being gutted for renovations.
4. His gut told him that this was the right choice.
5. They took out the gut of the machine to fix the problem.