Fuss to get navy ornament (5)
I believe the answer is:
adorn
'ornament' is the definition.
('adorn' can be a synonym of 'ornament')
'fuss to get navy' is the wordplay.
'fuss' becomes 'ado' ('ado' can be a synonym of 'fuss').
'to get' is a charade indicator (letters next to each other).
'navy' becomes 'rn' (abbreviation for Royal Navy).
'ado'+'rn'='ADORN'
(Other definitions for adorn that I've seen before include "Bedeck" , "Embellish, decorate" , "get dressed!" , "Deck" , "Festoon" .)