IPA: /ˈbækər/
KK: /ˈbækər/
A person or organization that supports someone or something, usually by providing money or resources.
The backer of the new film project provided the necessary funding to get it started.
Backer → It is formed from "back" (from Old English "bæc", meaning the rear or support) and "-er" (meaning a person who). A backer is a person who supports or provides assistance, often financially.
Think of someone who provides 'support' ('back') — the '-er' indicates that this person is the one giving that support.