In sex, empty seduction does not exist (4)
I believe the answer is:
isnt
'not exist' is the definition.
I can't tell whether this defines the answer.
'in sex empty seduction' is the wordplay.
'in' indicates putting letters inside.
'sex' becomes 'it' (a common euphemism).
'empty' suggests removing the centre.
'seduction' with its centre taken out is 'sn'.
'it' placed around 'sn' is 'ISNT'.
'does' acts as a link.
Can you help me to learn more?
(Other definitions for isnt that I've seen before include "When abridged, has none of the quality of" , "Is not (colloq.)" , "Tins (anag.)" , "Is not (abbrev.)" , "Does not happen to be" .)