Sci-fi fan respecting monarchs in match (7)
I believe the answer is:
trekkie
'sci-fi fan' is the definition.
(I've seen this before)
'respecting monarchs in match' is the wordplay.
'respecting' becomes 're' (regarding).
'monarchs' becomes 'kk' (I can't explain this - if you can you should believe this answer much more).
'in' indicates putting letters inside.
'match' becomes 'tie' (I've seen this before).
're'+'kk'='rekk'
'rekk' inserted into 'tie' is 'TREKKIE'.
(Other definitions for trekkie that I've seen before include "Fan of the TV series Star Trek" , "Sci-fi fan" , "one of his lovers?" .)