be a one

== English == === Verb === be a one (third-person singular simple present is a one, present participle being a one, simple past was a one, past participle been a one) (UK, dated, informal) To be amusing in a slightly challenging way. ==== See also ==== one of a kind ==== Further reading ==== “you are he is a one” in Longman Dictionary of Contemporary English, Longman. “be a one”, in Cambridge English Dictionary, Cambridge, Cambridgeshire: Cambridge University Press, 1999–present.