catamaran

The word 'catamaran' entered English in the 17th century from the Tamil language of South India, where 'kaṭṭumaram' described a type of raft. The Tamil term is a compound of 'kaṭṭu', meaning 'to tie' or 'binding', and 'maram', meaning 'tree' or 'wood'. Thus, the original, literal meaning was "tied wood," a perfectly logical description for a raft made by lashing logs together. English sailors adopted the term for the local vessels they encountered, and over time, its application narrowed and specialized to refer specifically to the modern, sleek, twin-hulled sailing vessel, preserving the core concept of a structure made from multiple connected units but with vastly refined technology.

This word is a loanword from Tamil, adopted into English. It does not consist of separable morphemes within the English language system.