Sandy hair? (6)
I believe the answer is:
strand
'hair?' is the definition.
(thesaurus)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for strand that I've seen before include "Thread - abandon" , "Shore; single fibre" , "Yarn - thread" , "that may be found by the sea" , "Beach - desert" .)