Servant, six-footer, in procession (7)
I believe the answer is:
pageant
'procession' is the definition.
(I've seen this before)
'servant six-footer' is the wordplay.
'servant' becomes 'page' (a royal servant).
'six footer' becomes 'ant' (an ant has six feet).
'page'+'ant'='PAGEANT'
'in' is the link.
(Other definitions for pageant that I've seen before include "Colourful display or parade" , "Series of tableaux etc" , "Costumed procession" , "Tableaux or dramatic scenes depicting historical events" , "Spectacular display" .)