Scarcity of thread (6)
I believe the answer is:
dearth
'scarcity of thread' is the definition.
(I've seen this before)
'of thread' is the wordplay.
'of' indicates anagramming the letters (the answer comes from or 'of' the letters).
'thread' with letters rearranged gives 'DEARTH'.
(Other definitions for dearth that I've seen before include "Scarceness or lack" , "Insufficient amount" , "Scarcity - lack" , "Severe lack" , "deficiency" .)