The word 'trimaran' is a modern 20th-century construction, formed by analogy with the older nautical term 'catamaran'. The prefix 'tri-', from Greek and Latin, directly indicates the vessel's defining feature of having three hulls. The second element '-maran' is borrowed from 'catamaran', which originates from the Tamil word for logs tied together. Therefore, the term's literal logic is transparent: a 'three-(hulled) catamaran', efficiently describing its structure in relation to its two-hulled predecessor.

Structure: tri (three) + maran (catamaran) - tri: From Latin and Greek tri-, meaning 'three'. A numerical prefix. - maran: A clipped form of 'catamaran', itself from Tamil kaṭṭumaram, meaning 'tied wood'. Serves as the base word for a multi-hulled vessel.