He attends to someones health after dinner (11)
I believe the answer is:
toastmaster
'he attends to someones' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'health after dinner' is the wordplay.
'health' becomes 'toast' (I've seen this before).
'after dinner' becomes 'master' (I can't justify this - if you can you should give a lot more credence to this answer).
'toast'+'master'='TOASTMASTER'
Can you help me to learn more?
(Other definitions for toastmaster that I've seen before include "Master of ceremonies at a banquet" , "Emcee at a banquet" , "Official at formal dinner" , "One proposing" , "One introducing" .)