Describes a person's unyielding, strong-willed nature; often used in a negative sense of being unreasonably stubborn. Can also imply a kind of tough-mindedness.
I'm at my wits' end with his stubborn attitude.
Sticking to your obstinacy isn't always wise.
意地っ張り emphasizes being willful or contrary, often over small matters; 剛腹 suggests a deeper, more ingrained obstinacy.
Standard kanji spelling; 剛 suggests strength or firmness, 腹 suggests belly/mind.
Variant spelling; 豪 suggests powerful or vigorous, but this form is less common.
Compound of 剛 (strong, firm) and 腹 (belly, mind), suggesting a 'firm belly/mind' i.e., an unyielding spirit. The exact historical derivation is uncertain.