not on

== English == === Phrase === not on (informal, British, Australia, Ireland) Unacceptable or impossible. 2003, Dan Connell (author), Lionel Cliffe and Basil Davidson (introduction), Taking on the Superpowers: Collected Articles on the Eritrean Revolution, 1976-1982, page 325, After a week or so, he and I determined that walking hundreds of miles behind guerrilla lines under these conditions was just not on for him, and he packed his equipment to return home. === References === “be not on”, in Cambridge English Dictionary, Cambridge, Cambridgeshire: Cambridge University Press, 1999–present. “not on”, in Collins English Dictionary. “it’s not on”, in Lexico, Dictionary.com; Oxford University Press, 2019–2022.