Headgear needed to run nonstop across Hawaii (5,3)
I believe the answer is:
opera hat
'headgear' is the definition.
(opera hat is a kind of headgear)
'to run nonstop across hawaii' is the wordplay.
I cannot really see how this works, but
'run' could be 'r' (cricket abbreviation) and 'r' is present in the answer.
'hawaii' could be 'ha' (abbreviation for Hawaii) and 'ha' is found within the answer.
This explanation may well be incorrect...
'needed' acts as a link.
(Other definitions for opera hat that I've seen before include "Formal theatre wear" , "Headgear to hear 14dn" , "Lid that collapses" , "that can be altered to flatter profile" , "garment in theatre?" .)