Charm maiden on course? (6)
I believe the answer is:
mascot
'charm' is the definition.
(synonyms)
'maiden on course?' is the wordplay.
'maiden' becomes 'm' (cricket abbreviation).
'on' means one lot of letters go next to another (in a down clue, letters appear on others).
'course?' becomes 'Ascot' (Ascot is a racecourse).
'm'+'ascot'='MASCOT'
(Other definitions for mascot that I've seen before include "One for good luck" , "Symbolic lucky figure" , "Team's lucky person/thing" , "It brings good luck" , "Team's good luck bringer" .)