Odious ultimately servile character, one lacking initiative (5)
I believe the answer is:
sheep
'one lacking initiative' is the definition.
Although both the answer and definition are singular nouns, I can't understand how one could define the other.
'odious ultimately servile character' is the wordplay.
'odious' becomes 'she' (I can't justify this - if you can you should believe this answer much more).
'ultimately' suggests the final letters.
'character' becomes 'p'.
The last letter of 'servile' is 'e'.
'she'+'e'+'p'='SHEEP'
Can you help me to learn more?
(Other definitions for sheep that I've seen before include "Cotswolds?" , "- may safely graze (Bach)" , "Eg, a merino" , "Source of mutton" , "Ruminant animal" .)