Gut instinct's three-quarters about outwardly tangible energy (9)
I believe the answer is:
intestine
'gut' is the definition.
(synonyms)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for intestine that I've seen before include "canal section" , "Part of the alimentary canal" , "Being gutted, one loses it" , "Some guts" .)