Working a lot with new nail (5)
I believe the answer is:
talon
'nail' is the definition.
(thesaurus)
'working a lot with new' is the wordplay.
'working' indicates anagramming the letters.
'with' is a charade indicator (letters next to each other).
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'a'+'lot'='alot'
'alot' is an anagram of 'talo'.
'talo'+'n'='TALON'
(Other definitions for talon that I've seen before include "Claw; undealt cards" , "Hooked claw; cards left after deal" , "The stock" , "Tonal (anag.)" , "part to make savage cuts" .)