Didn't feel well (5)
I believe the answer is:
ailed
'didn't feel well' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ailed that I've seen before include "was giving trouble" , "Didn't feel well" , "was on the blink?" , "Delia (anag.)" , "Became sick" .)