It's no longer in date so bride's pals return it discreetly (6)
I believe the answer is:
lapsed
'it's no longer in date' is the definition.
I can't tell whether this definition defines the answer.
'bride's pals return it discreetly' is the wordplay.
'LAPSED' is hidden back-to-front in amongst the letters.
But, I'm not sure how the hidden word is indicated.
'so' is the link.
Can you help me to learn more?
(Other definitions for lapsed that I've seen before include "No longer active or practising" , "Pleads, having failed to maintain standards" , "Expired, ran out" , "Expired over pedals" , "Expired or slipped back" .)