Asian joke involving a retired nurse once (8)
I believe the answer is:
japanese
'asian' is the definition.
(Japanese is an example)
'joke involving a retired nurse once' is the wordplay.
'joke' becomes 'jape' ('jape' can be a synonym of 'joke'**).
'involving' means one lot of letters goes inside another.
'retired' says the letters should be written in reverse.
'nurse once' becomes 'sen' (abbreviation for state-enrolled nurse).
'sen' reversed gives 'nes'.
'a'+'nes'='anes'
'jape' going around 'anes' is 'JAPANESE'.
(Other definitions for japanese that I've seen before include "From Honshu, perhaps" , "Nipponese" , "This nationality apes Jean" , "Language of Tokyo" , "One from Tokyo, say" .)