Deserter makes sailor get up (3)
I believe the answer is:
rat
'deserter' is the definition.
(both can mean a traitor)
'sailor get up' is the wordplay.
'sailor' becomes 'tar' (tar can mean a sailor).
'get up' says the letters should be written in reverse.
'tar' written backwards gives 'RAT'.
'makes' acts as a link.
(Other definitions for rat that I've seen before include "Rodent; traitor" , "one not going down with ship" , "Inform" , "shopper" , "Treacherous person" .)