Backer: noun - a supporter, especially someone who places a bet; someone who provides financial backing.
'Who's your backer for the play, Frances?' 'Oh, it's that marvellous tycoon with more money than sense; you know who I mean.'
'Zak is the most consistent backer of dud horses I've ever come across; hasn't won a bet for fifteen years.'
Pic: Wandering way; a rural scene from East Yorkshire.