モルモット

If モルモット looks like it should mean “marmot,” surprise: in Japanese it usually means guinea pig. This is one of the stronger animal false friends in katakana. The source is commonly given as Dutch marmot, but the Japanese animal is the small laboratory and pet guinea pig, not the mountain-dwelling marmot of English. The confusion is old. Dictionaries explain that when guinea pigs from South America entered European awareness, they were mixed up with the marmot, a different rodent. That mistaken label traveled on. Japanese borrowed the Dutch-looking name, and モルモット settled as the word for テンジクネズミ, the guinea pig. The meaning then took another step. Because guinea pigs became common experimental animals, モルモット also developed the figurative meaning “test subject” or “person used in an experiment.” A person may complain that they are being treated like a モルモット if a new method, medicine, policy, or product is being tried on them. For English-speaking learners, translation depends completely on context. The pet in a cage is a guinea pig. The animal called a marmot in English is normally マーモット in Japanese. And the human metaphor is “test subject,” “guinea pig,” or “experimental subject,” not a literal marmot. So モルモット is a word with three twists: borrowed through Dutch, attached to the wrong animal family, and then turned into a metaphor. It is cute in a pet shop, serious in a lab, and suspicious in a complaint.