IPA: /ˈfɒstərə/
KK: /ˈfɔstərər/
A person who takes care of and supports someone, often a child, in a nurturing way.
The fosterer provided a loving home for the children in need.
Fosterer → It is formed from "foster" (from Old English *fostrian*, meaning to nourish or rear) and "-er" (meaning a person who). A fosterer is a person who nourishes or takes care of someone, typically a child, in a nurturing role.
Think of someone who 'nourishes' or 'cares for' others — that's what a fosterer does, as they are a person who provides care.