Father’s nose broken by end of large toy weapon (10)
I believe the answer is:
peashooter
'toy weapon' is the definition.
(toy for shooting dried peas)
'father's nose broken by end of large' is the wordplay.
'father's' becomes 'pa's' (pa can mean dad or father).
'nose' becomes 'hooter' (hooter can informally mean someone's nose).
'broken by' means one lot of letters goes inside another (inserted letters break into the word).
'end of' indicates one should take the final letters.
The final letter of 'large' is 'e'.
'pas'+'hooter'='pashooter'
'pashooter' going around 'e' is 'PEASHOOTER'.
(Other definitions for peashooter that I've seen before include "Primitive weapon" , "child's toy" , "Child's "gun"" , "Toy weapon" .)