Boy gets impetuous and bold (5)
I believe the answer is:
brash
'bold' is the definition.
(I've seen this before)
'boy gets impetuous' is the wordplay.
'boy' becomes 'b' (I can't explain this - if you can you should give a lot more credence to this answer).
'gets' is a charade indicator (letters next to each other).
'impetuous' becomes 'rash' (I've seen this before).
'b'+'rash'='BRASH'
'and' acts as a link.
Can you help me to learn more?
(Other definitions for brash that I've seen before include "Cocky and tactless" , "Tasteless in appearance" , "Loud and rude" , "Crudely showy; bumptious" , "Pushy" .)