James Bond's boss is royal, but a cheapskate (5)
I believe the answer is:
miser
'a cheapskate' is the definition.
(I've seen this before)
'james bond's boss is royal' is the wordplay.
'james bond's boss' becomes 'm' (M is the head of MI6 in the James Bond series).
'royal' becomes 'er' (abbreviation for Elizabeth Regina).
'm'+'is'+'er'='MISER'
'but' acts as a link.
(Other definitions for miser that I've seen before include "Person who hoards money" , "One sparing with money" , "auger" , "man, that's close" , "not a spendthrift" .)