Lack of cash concealed by trendy clothing (15)
I believe the answer is:
underinvestment
'lack of cash' is the definition.
The definition suggests a singular noun which matches the answer.
'concealed by trendy clothing' is the wordplay.
I cannot quite see how this works, but
'trendy' could be 'in' ('in' can mean fashionable) and 'in' is found within the answer.
'clothing' could be 'vestment' (vestment is a kind of clothing) and 'vestment' is found in the answer.
The remaining letters 'under' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Another definition for underinvestment that I've seen is " low funding".)