One girl's name for a resounding defeat? (5)
I believe the answer is:
floss
'one' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'girl's name for a resounding defeat?' is the wordplay.
'girl's name' becomes 'Flo'.
'for' means one lot of letters go next to another.
'a resounding defeat?' becomes 'ss' (I can't justify this - if you can you should believe this answer much more).
'flo'+'ss'='FLOSS'
Can you help me to learn more?
(Other definitions for floss that I've seen before include "Dental thread" , "advice of dentist?" , "teeth cleaner" , "Kind of down" , "flower in Victorian novel" .)