Applaud honoured companion, always (5)
I believe the answer is:
cheer
'applaud' is the definition.
(I know that cheer is a is a more specific form of the action applaud)
'honoured companion always' is the wordplay.
'honoured companion' becomes 'CH' (Companion of Honour).
'always' becomes 'eer' (poetic way of saying ever).
'ch'+'eer'='CHEER'
(Other definitions for cheer that I've seen before include "hurrah" , "party refreshment?" , "Give comfort or support to" , "Fare" , "Applaud and acclaim" .)