Tuff

Part of speech: noun

Pronunciation: /tʌf/

Definitions

1. A lightweight volcanic rock that forms from collected ash and typically serves as a construction material due to its manageable weight
2. This porous stone arises from volcanic ash solidifying, making it useful in various building applications
3. A type of porous rock formed from volcanic ash that is commonly utilized in construction due to its lightness and insulating properties

Etymology: The most surprising thing about this word is that its ancestor was a term for a soft, crumbly stone, not a sturdy one. The Latin "tōfus" referred to porous rock, and it passed through Italian "tufo" and French "tuffe" or "tuf" before reaching English. Italian builders and geologists used the term for the light, spongy volcanic deposits common around Rome and Naples, which were easy to cut into blocks. The word has a twin in English: "tufa" is a doublet, meaning the same Latin root arrived by a different route. Both words share the sense of porous stone formed from volcanic material or from mineral deposits, but "tufa" came more directly from Italian, while "tuff" came through French. Its spelling and pronunciation make it look like a cousin of "tough," but that is only a coincidence of sound. The two words have unrelated histories, and the resemblance is an accident of how the letters came to be written.