The average false-hearted woman (6)
I believe the answer is:
normal
'the average' is the definition.
(I've seen this before)
'false-hearted woman' is the wordplay.
'false' becomes 'norma' (I can't justify this - if you can you should give a lot more credence to this answer).
'hearted' indicates the central letters.
'woman' becomes 'Ellen' (woman's name).
The central letter of 'ellen' is 'l'.
'norma'+'l'='NORMAL'
Can you help me to learn more?
(Other definitions for normal that I've seen before include "Common" , "Popular" , "Unexceptional" , "Conforming to a standard" , "'Standard, conventional (6)'" .)