sell up verb 3sell-up noun 1forms 4 verb3 •To sell one's business or other major asset (such as a home). •(UK) To sell all (of the assets of a company or person), in order to reduce its debts or gain liquid money. •To upsell.Attracting consumers with a low-priced feature item and then pointing out weaknesses in order to sell up to a more expensive […] — 2001 sell-up noun1 •The act or process of selling one's property or business, typically because of debts or financial considerations. formssold up · selling up · sells up · sell-ups