Slump includes credit squeeze (5)
I believe the answer is:
scrag
'squeeze' is the definition.
(scragging is a kind of squeezing)
'slump includes credit' is the wordplay.
'slump' becomes 'sag' (I've seen this before).
'includes' means one lot of letters goes inside another.
'credit' becomes 'cr'.
'sag' placed around 'cr' is 'SCRAG'.
(Other definitions for scrag that I've seen before include "Bony part of the neck" , "Collar" , "Lean end of mutton neck" , "The inferior end of a neck of mutton" , "End of neck - beat up" .)