Blade large Italian lifted in quarrel (8)
I believe the answer is:
stiletto
'blade' is the definition.
(I know that stiletto is a type of blade)
'large italian lifted in quarrel' is the wordplay.
'large' becomes 'L' (eg in clothes sizes).
'italian' becomes 'it' (abbreviation for Italian).
'lifted' shows that the letters should be reversed in order (going up in down clue).
'in' means one lot of letters goes inside another.
'quarrel' becomes 'set to' (a set-to is a confrontation or disagreement).
'l'+'it'='lit'
'lit' written backwards gives 'til'.
'til' put within 'setto' is 'STILETTO'.
(Other definitions for stiletto that I've seen before include "Slender dagger, heel" , "Dagger; tapered heel" , "Tapering dagger" , "Long dagger" , "Possible cause of stabbing pains" .)