Mistake forgetting name: one may have blown it (5)
I believe the answer is:
bugle
'it' is the definition.
The definition suggests a singular noun which matches the answer.
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for bugle that I've seen before include "Creeping plant with blue flowers" , "Bit of brass" , "Brass instrument without valves" , "Trumpet-like instrument" , "Does it call" .)