From Longman Dictionary of Contemporary Englishtennerten‧ner /ˈtenə $ -ər/ noun [countable] British English informal PEC£10 or a ten-pound note Can you lend me a tenner?
Examples from the Corpus
tenner• For a tenner, I snapped up a dinner-jacket for an office party, and gave it back afterwards.• Grey Wig pushed a tenner in.• I only spent a tenner all week.• Look at the temptation: a pill that will give you euphoria and energy all night long for less than a tenner.• There's one on now: for less than a tenner anyone can have a four point safety check.• Income: Lend us a tenner?• The Feedback tenner will go to whoever suggests the best sponsored name.From Longman Business Dictionarytennerten‧ner /ˈtenə-ər/ noun [countable] British English informal ten pounds, especially in the form of a ten pound noteCan you lend me a tenner? 