‘臭味相投’ literally means 'stinky smells meet and align'—a vivid, ironic idiom describing people who share similar (usually negative or disreputable) tastes, values, or habits. Though 臭 (chòu) means 'smelly' and 味 (wèi) means 'smell/taste', together they metaphorically represent moral or aesthetic inclinations—especially undesirable ones like dishonesty, laziness, or recklessness. The phrase carries a strong tone of disapproval or wry mockery.

This idiom is used exclusively for people—not objects or animals—and always implies mutual attraction based on shared flaws or low standards. It’s common in informal speech and writing, often with humorous or sarcastic intent. While it sounds animal-related (e.g., dogs sniffing each other), its usage is strictly human-centered and social-psychological. Historically, it originates from classical texts comparing moral alignment to scent affinity, but today it’s almost always pejorative.