Recalled endless sex party with bit of tit for tat (4)
I believe the answer is:
grot
'tat' is the definition.
(both can mean rubbish)
'recalled endless sex party with bit of tit' is the wordplay.
'recalled' says the letters should be written in reverse.
'endless' means to remove the last letter.
'sex party' becomes 'orgy' (group sex event).
'with' says to put letters next to each other.
'bit of' indicates taking the first letters.
The initial letter of 'tit' is 't'.
'orgy' with its last letter removed is 'org'.
'org' reversed gives 'gro'.
'gro'+'t'='GROT'
'for' acts as a link.
(Other definitions for grot that I've seen before include "Rubbish (slang); picturesque cave (poet.)" , "tat" , "Refuse" , "Filth" .)