Stressed about ringlet (5)
I believe the answer is:
tress
'ringlet' is the definition.
(I've seen this in another clue)
'stressed about' is the wordplay.
'about' indicates the answer is hidden within the clue (the clue goes around or about the answer).
'TRESS' is hidden in the letters of 'stressed'.
(Other definitions for tress that I've seen before include "Long piece of hair" , "Braid of hair" , "Bit of hair" , "Obsolete support" , "Long lock or plait of hair" .)