坚定 (jiāndìng) is an adjective meaning 'firm' or 'resolute', describing a person’s unwavering attitude, belief, or determination. The first character 坚 (jiān) means 'hard', 'solid', or 'strong', often used metaphorically for mental or moral strength (e.g., 坚强). The second character 定 (dìng) means 'to settle', 'to fix', or 'to decide', suggesting stability and clarity of purpose. Together, 坚定 conveys the idea of being mentally anchored — not easily swayed by doubt, pressure, or changing circumstances.

This word commonly modifies nouns like 信念 (belief), 立场 (position/stance), 决心 (determination), or 态度 (attitude). It’s frequently used in formal speech, writing, and contexts involving values, ethics, or long-term goals — such as political discourse, personal development, or moral education. While it carries positive connotations of integrity and courage, it can occasionally imply stubbornness if context suggests inflexibility without reason.