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 an anagram.
'dearth' is an anagram of 'THREAD'.
'of' acts as a 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" .)