Strange dearth of yarn (6)
I believe the answer is:
thread
'yarn' is the definition.
(I know that thread is a type of yarn)
'strange dearth' is the wordplay.
'strange' indicates anagramming the letters.
'dearth' with letters rearranged gives 'THREAD'.
'of' is the link.
(Other definitions for thread that I've seen before include "Train of thought - screw feature" , "Cord - Internet chat room discussion" , "Connecting line" , "Sewing chord" , "Strand, cord" .)