/sel"owt'/ , n.
1. an act or instance of selling out.
2. an entertainment, as a show or athletic event, for which all the seats are sold.
3. Informal. a person who betrays a cause, organization, or the like; traitor.
4. Informal. a person who compromises his or her personal values, integrity, talent, or the like, for money or personal advancement.
[ 1855-60, Amer.; n. use of v. phrase sell out ]