Able to be turned into real money. You say it about a cheque, a voucher, a prize ticket, a savings bond — a piece of paper that promises money, where the question is whether you can actually go somewhere and collect. A cashable cheque is one the bank will pay out on. If the bank refuses because the date has passed or the account is empty, the cheque is not cashable. The word is quiet and practical: banking, insurance, small print. Nobody uses it about a person or a feeling. Canadian and American banks use it a lot for savings products — a cashable GIC is one you can break early and take your money out of, instead of waiting the full five years — and there the word is really about freedom, not just possibility. Note that "cashable" is not the everyday choice in speech; people usually just say "can I cash this?"