IPA: /ˈfɒstərɪdʒ/
KK: /ˈfɔstərɪdʒ/
The state or condition of being raised by someone who is not one's biological parent, often involving care and support.
The fosterage of children can provide them with a loving home when their biological parents are unable to care for them.
Fosterage → It is formed from "foster" (from Old English *fostrian*, meaning to nourish or support) and "-age" (a suffix indicating a state or condition). The word "fosterage" refers to the state or condition of being fostered or raised by someone other than one's biological parents.
Think of 'nourishing' ('foster') someone in a special 'state' ('-age') — that's why fosterage means the condition of being raised by someone else.