Banknote (6)
'banknote' is the definition.
(fiver is a kind of banknote)
This is all the clue.
(Other definitions for fiver that I've seen before include "money" , "Bank note" , "Note worth 500p" , "Banknote (informal)" , "Smallest English note" .)
'banknote' is the definition.
(I know that tenner is a type of banknote)
This is the entire clue.
(Other definitions for tenner that I've seen before include "Ten-pound note (inf.)" , "Ten pound note (colloq.)" , "Two fivers" , "Banknote (informal); sounds like a singer" , "note form" .)