schoolboy error

== English == === Pronunciation === === Noun === schoolboy error (plural schoolboy errors) (UK, informal, idiomatic) A fundamental, simple mistake. Synonym: rookie mistake ==== Translations ==== ==== Further reading ==== “schoolboy error”, in Cambridge English Dictionary, Cambridge, Cambridgeshire: Cambridge University Press, 1999–present. “schoolboy error”, in Lexico, Dictionary.com; Oxford University Press, 2019–2022.