Philosopher follows the first bride’s outfit (9)
I believe the answer is:
trousseau
'bride's outfit' is the definition.
(I've seen this before)
'philosopher follows the first' is the wordplay.
I cannot really see how this works, but
'philosopher' could be 'rousseau' (Rousseau is an example) and 'rousseau' is located in the answer.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found within the answer.
This accounts for all the letters.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for trousseau that I've seen before include "Clothes etc. collected by a bride for her marriage" , "Clothes collected for a purpose" , "Bride's accoutrements" , "Bridal outfit" , "A bride's collection of clothing" .)