Father certainly repelled love goddess (5)
I believe the answer is:
freya
'love goddess' is the definition.
(I've seen this before)
'father certainly repelled' is the wordplay.
'father' becomes 'fr' (abbreviation as in a priest's title).
'certainly' becomes 'aye' (both can be used to answer in the affirmative).
'repelled' is a reversal indicator.
'aye' written backwards gives 'eya'.
'fr'+'eya'='FREYA'
(Other definitions for freya that I've seen before include "Female" , "Norwegian goddess" , "Norse love goddess" .)