Outer layer broke, almost entirely (4)
I believe the answer is:
skin
'outer layer' is the definition.
(I've seen this before)
'broke almost entirely' is the wordplay.
'broke' becomes 'skint' (both can mean struggling financially).
'almost entirely' means to remove the last letter (most but not all of the word).
'skint' with its final letter removed is 'SKIN'.
(Other definitions for skin that I've seen before include "Living tissue" , "coat" , "Outer layer of a fruit or vegetable" , "Swindle" , "Dermis" .)