Honour suet oddly as fat (5)
I believe the answer is:
obese
'fat' is the definition.
(similar in meaning)
'honour suet oddly' is the wordplay.
'honour' becomes 'obe' (Order of the British Empire award).
'oddly' indicates alternate letters (letters in the odd-numbered positions are used).
The alternating letters of 'suet' are 'se'.
'obe'+'se'='OBESE'
'as' acts as a link.
(Other definitions for obese that I've seen before include "Grossly overweight" , "Morbidly fat" , "Unhealthily large" , "in need of slimming down" , "Carrying far too much weight" .)