Only females love males to wear father's spectacles (9)
I believe the answer is:
phenomena
'spectacles' is the definition.
(I've seen this before)
'only females love males to wear father's' is the wordplay.
'only females' becomes 'hen' (as in a hen night).
'love' becomes 'o' (love means zero in tennis).
'males' becomes 'men' (man is a kind of male).
'to wear' is an insertion indicator (to wear something is to be covered up by it).
'father' becomes 'pa' (pa can mean dad or father).
'hen'+'o'+'men'='henomen'
'henomen' inserted inside 'pa' is 'PHENOMENA'.
(Other definitions for phenomena that I've seen before include "Remarkable occurrences" , "spectacles" , "Observed events - remarkable things" , "strange doings!" , "Happenings" .)