Poorly (3,2,5)
'poorly' is the definition.
(I know that poorly can be written as ill)
This is the entire clue.
(Other definitions for ill that I've seen before include "Unwell, sick" , "Not in good health" , "Not well, sick" , "Indisposed" , "I will (abbrev.) (1'2)" .)
(Other definitions for out of sorts that I've seen before include "Not well" , "Slightly unwell" , "under the weather" , "Slightly unhappy" , "Lacking variety" .)