A projection, flap, or short strip attached to an object to facilitate opening, handling, or identification. A small, usually decorative flap or tongue on a garment. A small auxiliary airfoil that is attached to a larger one and that helps stabilize an aircraft. A pull-tab. To supply with a tab or tabs. Informal A bill or check, such as one for a meal in a restaurant. Informal Cost; price: The tab for upgrading the computers would be high. A tabulator on a typewriter. Computer Science A key on a computer keyboard that, when pressed, inserts a special ASCII character used for formatting text, as in indenting a line or block of text. Computer Science This special ASCII character. To press the tab on a typewriter or computer keyboard: Tab over to the next column. keep tabs on Informal To observe carefully: Let's keep tabs on expenditures.