One who prefers to be lacking in spirit (11)
I believe the answer is:
teetotaller
'one who prefers' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'be lacking in spirit' is the wordplay.
I cannot quite see how this works, but
'be' could be 'total' (totaling is a kind of being) and 'total' is found in the answer.
This explanation may well be incorrect...
'to' acts as a link.
Can you help me to learn more?
(Other definitions for teetotaller that I've seen before include "One dry" , "One abstaining from alcohol" , "Non-drinker" , "Rechabite" , "Abstainer from alcohol" .)