Longs for order during main revolution (5)
I believe the answer is:
aches
'longs for' is the definition.
(I've seen this in another clue)
'order during main revolution' is the wordplay.
'order' becomes 'CH' (abbreviation for Companion of Honour).
'during' indicates putting letters inside.
'main' becomes 'sea' (the main is an old name for the sea).
'revolution' says the letters should be written in reverse.
'sea' written backwards gives 'aes'.
'ch' going inside 'aes' is 'ACHES'.
(Other definitions for aches that I've seen before include "Constant pains" , "discomfort" , "Dull persistent pains" , "sign of suffering" , "Pains, hurts" .)