Not feeling too well (5,3,7)
I believe the answer is:
under the weather
'not feeling too well' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for under the weather that I've seen before include "Sickening" , "put umbrellas up here?" , "Seedy" , "Sick" , "the worse for wear" .)