IPA: /ˌʌnəˈfɔːrdəbl/
KK: /ʌnəˈfɔrdəbl/
Something that is too expensive for most people to buy or pay for.
Many families find housing in the city to be unaffordable.
Unaffordable → It is formed from "un-" (meaning not) and "affordable" (from Old French *afordabil*, meaning able to be afforded). The word "unaffordable" means not able to be afforded or too expensive to buy.
Think of 'not' ('un-') being added to 'able to be afforded' — this helps you remember that 'unaffordable' means something that cannot be afforded.