Definition of "sustainer"
A person or thing that sustains.
Quotations
[…] not One in Fifty, of our Men of Fashion, or of Quality, as they call themselves, has an Understanding that is able to go alone. They are forc’d, therefore, to wait ’till they have their Sustainer’s Opinion to lean against, before they dare venture upon the Praise, even of what they are inclinable to think favourably of […]
1724, Aaron Hill and William Bond, The Plain Dealer, No. 36, 24 July, 1724, London: S. Richardson & A. Wilde, p. 296