The story
- Proto-Indo-European*h₁én
- Proto-Indo-European*h₁n̥tér
- Proto-Italic*n̥ter
- Latininter
- Latininter-
- Englishinter-
- Englishnational
- English todayinternational
From inter- + national. Introduced in modern English by Jeremy Bentham in his An Introduction to the Principles of Morals and Legislation, 1780.
Etymology from Wiktionary, CC BY-SA 4.0.