Irritable, score having replaced everything in tally (6)
I believe the answer is:
tetchy
'irritable' is the definition.
(synonyms)
'score having replaced everything in tally' is the wordplay.
I cannot really understand how this works, but
'score' could be 'etch' (etch can mean to score or carve into something) and 'etch' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
(Other definitions for tetchy that I've seen before include "Ratty" , "Touchy" , "Easily provoked" , "Bad-tempered" , "Cantankerous" .)