"Gut with fire" is an expression that implies intense emotion or passion. Synonyms for this phrase include "burn with intensity," "ignite from within," and "enflame with fervor." Other similar words that could be used to convey the same meaning include "ignite," "spark," "kindle," "incite," "stir up," "rouse," and "arouse." All of these words convey a sense of strong emotions and a burning desire within oneself that cannot be quenched. Whether used in a metaphorical sense or in a literal context, these synonyms capture the same vivid imagery and intensity as the phrase "gut with fire".