The term 'feel in one's ___' can be completed with two different answers: 'GUT' (3 letters) and 'BONES' (5 letters). The phrase 'feel in one's GUT' is an idiom that means to have a strong intuition or feeling about something. It is often used to describe a person's instinctive reaction to a situation. On the other hand, the phrase 'feel in one's BONES' is an expression that is used to describe a deep-seated feeling or knowledge that something is true. This phrase is often used to describe a feeling of certainty or conviction about something.