It gets stuck quietly in (3)
I believe the answer is:
pin
'it gets stuck' is the definition.
The definition suggests a singular noun which matches the answer.
'quietly in' is the wordplay.
'quietly' becomes 'p' (p for piano and quiet).
'p'+'in'='PIN'
Can you help me to learn more?
(Other definitions for pin that I've seen before include "Debit-card number" , "Fixing device" , "Secure" , "Badge" , "Skittle; chess attack" .)