Become angry, leave part of pool (2,3,3,4,3)
I believe the answer is:
go off the deep end
'become angry' is the definition.
I know nothing about this answer so I can't judge whether this works.
'leave part of pool' is the wordplay.
I cannot really see how this works, but
'leave' could be 'gooff' (I've seen this before) and 'gooff' is present in the answer.
'part' could be 'deepend' (I have seen 'part of pool' mean 'deep end' so perhaps 'part' could also mean 'deep end') and 'deepend' is found in the answer.
The remaining letters 'the' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for go off the deep end that I've seen before include "See red" , "storm?" , "turn where it's safe to dive?" , "Be reluctant to enter part of pool" , "Flip" .)