忌妒 (jì dù) is a verb meaning 'to be jealous of' or 'to envy' — specifically, to feel resentment or ill will toward someone because of their advantages, such as success, possessions, talents, or relationships. The character 忌 (jì) means 'to avoid' or 'to fear', often implying aversion or taboo; 妒 (dù) means 'to be envious' or 'to begrudge'. Together, they form a compound that emphasizes the negative, emotionally charged aspect of jealousy — not just mild admiration, but discomfort or hostility arising from comparison.

This word is commonly used in written and formal spoken Chinese, especially when describing interpersonal tension, social competition, or moral judgment. It carries a stronger, more critical connotation than the neutral term 嫉妒 (jí dù), and is often associated with pettiness, insecurity, or harmful behavior. While it can appear in everyday conversation, it’s more frequent in literature, news reports, or psychological discussions about toxic emotions.