nicotine

Nicotine comes from French nicotine, formed from the surname Nicot plus the ending -ine. It honors Jean Nicot, the French ambassador to Portugal who sent tobacco seeds back to France in 1561.

The word moved from being a personal name attached to a plant to the name of the chemical compound found in that plant, as it was borrowed into English from French.

The -ine ending here traces back through French -in to Latin -īnus, a suffix pattern used to form many chemical and descriptive terms, though no specific cognate word is given in the facts.