The story
From Marienbad + -ism, from the French New Wave film L'Année dernière à Marienbad (Last year at Marienbad).
Etymology from Wiktionary, CC BY-SA 4.0.
Today it means: A style of film that has an enigmatic narrative structure coupled with a dreamlike uncertainty over what is real and what is imagined. Full definition →
From Marienbad + -ism, from the French New Wave film L'Année dernière à Marienbad (Last year at Marienbad).
Etymology from Wiktionary, CC BY-SA 4.0.