Definitions: (1) daring or courageous; nervy; plucky; (2) robust, vigorous
Idiom: Intestinal fortitude.
Quotes:
• You need the right balance between data and gut feeling. — Torger Christian “Toto” Wolff (1972-) Austrian motorsport executive
• Life is hard. Life is difficult. Life is going to punch you in the gut. But when you change your attitude, you change your behavior. When your behavior changes, so do your results. — William Ballard Hurd (1977-) American politician
Comment: If you are going to be gutsy you better also be honest or it will come back to bite you.