It could be a local number (11)
I believe the answer is:
anaesthetic
'number' is the definition.
(something which 'numbs' you)
'it could be a local' is the wordplay.
I cannot quite understand how this works, but
'it' could be 't' (abbreviation. e.g. in 'tis) and 't' is present in the answer.
'a' could be 'an' and 'an' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for anaesthetic that I've seen before include "Number of bodies - can hesitate (anag)" , "used in theatre" , "Numbing substance" , "painkiller" , "Drug that causes temporary loss of feeling" .)