IPA: //ʌnˈsɛl.ə.bəl//
KK: /ʌnˈsɛləbəl/
Something that cannot be sold or is very difficult to sell.
The old car was considered unsellable due to its many problems.
Unsellable → It is formed from "un-" (meaning not) and "sell" (from Old English "sellan", meaning to give or deliver). The suffix "-able" (meaning capable of) indicates that something is not capable of being sold. Thus, "unsellable" means something that cannot be sold.
Think of something that is 'not' ('un-') able to be 'sold' — that's why unsellable means it cannot be sold.