Gentleman showing some desire (3)
I believe the answer is:
sir
'gentleman' is the definition.
(a man may be addressed as sir)
'some desire' is the wordplay.
'some' says the answer is hidden in the clue (some parts of the word are used).
'SIR' is hidden in the letters of 'desire'.
'showing' acts as a link.
(Other definitions for sir that I've seen before include "Gentleman's form of address" , "Male title of respect" , "Respectful address for a man" , "Term of address for a gentleman" , "Feted fellow" .)