Sell  —v. (past and past part. Sold) 1 exchange or be exchanged for money (these sell well). 2 stock for sale (do you sell eggs?). 3 (foll. By at, for) have a specified price (sells at £5). 4 (also refl.) Betray or prostitute for money etc. 5 (also refl.) Advertise or publicize (a product, oneself, etc.). 6 cause to be sold (name alone will sell it). 7 colloq. Make (a person) enthusiastic about (an idea etc.). —n. Colloq. 1 manner of selling (soft sell). 2 deception; disappointment.  sell down the river see *river. Sell off sell at reduced prices. Sell out 1 (also absol.) Sell (all one's stock, shares, etc.). 2 betray; be treacherous or disloyal. Sell short disparage, underestimate. Sell up sell one's business, house, etc. [old english]