Sharp needs help securing credit (5)
I believe the answer is:
acrid
'sharp' is the definition.
(I've seen this in another clue)
'help securing credit' is the wordplay.
'help' becomes 'aid' (synonyms).
'securing' indicates putting letters inside.
'credit' becomes 'cr' (abbreviation).
'aid' placed around 'cr' is 'ACRID'.
'needs' acts as a link.
(Other definitions for acrid that I've seen before include "Painfully pungent" , "causing corrosion" , "Direly pungent" , "Stinging" , "Sour, pungent" .)