Looking back, no hand cut by back of the knife? (6)
I believe the answer is:
weapon
'knife?' is the definition.
(knife is a kind of weapon)
'looking back no hand cut by back of the' is the wordplay.
'looking back' says the letters should be written backwards.
'hand' becomes 'paw' (synonyms).
'cut by' indicates putting letters inside (some letters cut into others).
'back of' says to take the final letters.
The last letter of 'the' is 'e'.
'no'+'paw'='nopaw'
'nopaw' enclosing 'e' is 'nopaew'.
'nopaew' written backwards gives 'WEAPON'.
(Other definitions for weapon that I've seen before include "Thing used to inflict bodily harm" , "Instrument to kill or injure" , "Instrument of offence or defence" , "Feel a great desire for" , "Offensive tool" .)