Animal used in ceremony, a lamb (5)
I believe the answer is:
nyala
'animal' is the definition.
(I've seen this before)
'in ceremony a lamb' is the wordplay.
'in' indicates the answer is hidden within the clue.
'NYALA' can be found hidden inside 'ceremony a lamb'.
'used' is the link.
(Other definitions for nyala that I've seen before include "Large African antelope" , "Spiral-horned antelope" , "Ruminant" , "wild animal" , "African animal" .)