Make an embarrassing mistake with a bell (4,1,7)
I believe the answer is:
drop a clanger
'bell' is the definition.
I don't know anything about this answer so I can't tell whether this works.
'make an embarrassing mistake with a' is the wordplay.
'make an' becomes 'drop' (I can't justify this - if you can you should believe this answer much more).
'embarrassing mistake' becomes 'clanger' (I've seen this before).
'with' means one lot of letters go next to another.
'clanger' put after 'a' is 'aclanger'.
'drop'+'aclanger'='DROP A CLANGER'
Can you help me to learn more?
(Other definitions for drop a clanger that I've seen before include "Say something tactless - make stupid blunder" , "and ignore someone making changes?" , "Be indiscreet" , "Blunder seriously" , "Say something very embarrassing" .)