固执 (gù zhí) is an adjective meaning 'stubborn' or 'obstinate' — describing someone who stubbornly sticks to their own opinions, habits, or decisions despite reason, evidence, or others’ advice. The character 固 (gù) means 'firm', 'solid', or 'fixed', while 执 (zhí) means 'to hold' or 'to grasp'. Together, they literally convey 'holding firmly' — suggesting an unyielding mental posture. It carries a mildly negative connotation and is commonly used in interpersonal contexts, especially when someone refuses to change their mind even when persuaded.

This word often appears in descriptions of personality traits, arguments, or everyday disagreements — for example, about food preferences, study methods, or social plans. While it can occasionally be neutral or even slightly positive when implying strong principles (e.g., 'stubbornly upholding justice'), in most daily usage it signals inflexibility that causes friction. It’s more formal than colloquial alternatives like 死脑筋 (sǐ nǎo jīn, 'thick-headed') and is frequently used in written Chinese and mature spoken discourse.