Attendant trailed by worker in procession (7)
I believe the answer is:
pageant
'procession' is the definition.
(I've seen this before)
'attendant trailed by worker' is the wordplay.
'attendant' becomes 'page' (page is a kind of attendant).
'trailed by' is a charade indicator (letters next to each other) (some letters trail after others).
'worker' becomes 'ant' (worker is a type of ant).
'page'+'ant'='PAGEANT'
'in' is the link.
(Other definitions for pageant that I've seen before include "Parade with tableaux" , "Spectacular display" , "Scene moving" , "Extravagant dramatic display" , "Make public spectacle" .)