A tenor supporting Queen, Love or Muse (5)
I believe the answer is:
erato
'muse' is the definition.
(Erato is an example)
'a tenor supporting queen love' is the wordplay.
'tenor' becomes 't'.
'supporting' says to put letters next to each other (in a down clue, some letters go below others).
'queen' becomes 'er' (abbreviation for Elizabeth Regina).
'love' becomes 'o' (In tennis, 'love' means 'zero').
'a'+'t'='at'
'at' put after 'er' is 'erat'.
'erat'+'o'='ERATO'
'or' acts as a link.
(Other definitions for erato that I've seen before include "Who may have inspired poetry" , "Lyric poetry's muse" , "Poet's muse" , "Greek muse of lyric and love poetry" , "One inspiring" .)