Unwilling to make a halt since there's nothing in it (5)
I believe the answer is:
loath
'unwilling' is the definition.
(similar in meaning)
'a halt since there's nothing in it' is the wordplay.
I cannot quite understand how this works, but
'a' is within the answer.
'nothing' could be 'o' (looks like zero - 0) and 'o' is found in the answer.
'it' could be 't' (abbreviation. e.g. in 'tis) and 't' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
'to make' is the link.
Can you help me to learn more?
(Other definitions for loath that I've seen before include "Unwilling" , "Reluctant or averse" , "Dislike intensely" , "Hateful" .)