Added 9 October 2026 arnold noun Categories: PeopleUncommon Words noun ! Definition from WordNet 3.1, Princeton University. More about arnold at Wordnik → Where our words come from → English poet and literary critic (1822-1888). United States general and traitor in the American Revolution; in 1780 his plan to surrender West Point to the British was foiled (1741-1801). Related Words: forsterchiariarnoarnearniarnasarniearnyarnaldoarnoldoarnulfarnot Back to today's word