Tatty sort of dagger (6)
I believe the answer is:
ragged
'tatty' is the definition.
(synonyms)
'sort of dagger' is the wordplay.
'sort of' indicates anagramming the letters.
'dagger' is an anagram of 'RAGGED'.
(Other definitions for ragged that I've seen before include "Wearing torn clothes or lacking smoothness" , "taunted" , "Like worn-out clothing" , "down at heel" , "being poorly dressed" .)