Warehouse articles containing phosphorus degenerate rapidly (2,4,3,3)
I believe the answer is:
go down the pan
'degenerate rapidly' is the definition.
I don't know anything about this answer so I can't judge whether this works.
'warehouse articles containing phosphorus' is the wordplay.
'warehouse' becomes 'godown' (godown is a kind of warehouse).
'articles' becomes 'thean' (two examples of the part-of-speech: the+an).
'containing' means one lot of letters goes inside another.
'phosphorus' becomes 'P' (P is the chemical symbol for phosphorus).
'thean' going around 'p' is 'thepan'.
'godown'+'thepan'='GO DOWN THE PAN'
Can you help me to learn more?
(Other definitions for go down the pan that I've seen before include "Fail utterly" , "deteriorate rapidly" .)