Sounds like a shortage of resin (3)
I believe the answer is:
lac
'resin' is the definition.
(resin secreted by lac insects)
'sounds like a shortage' is the wordplay.
'sounds like' indicates a 'sounds like' (homophone) clue.
'a shortage' becomes 'lack' (a lack is a shortage of something).
'lack' sounds like 'LAC'.
'of' is the link.
(Other definitions for lac that I've seen before include "Natural product" , "Huge sum" , "One hundred thousand" , "Resinous substance an insect secretes" , "Catalyst" .)