|a. & n.||1.||(Mus.) The higher part of the scale. See Alto.|
|Noun||1.||ALT - angular distance above the horizon (especially of a celestial object)|
|(character)||alt - /awlt/ 1. The alt modifier key on many
keyboards, including the IBM PC. On some keyboards and
operating systems, (but not the IBM PC) the alt key sets bit
7 of the character generated.|
See bucky bits.
2. The "clover" or "Command" key on a Macintosh; use of this term usually reveals that the speaker hacked PCs before coming to the Mac (see also feature key). Some Mac hackers, confusingly, reserve "alt" for the Option key (and it is so labelled on some Mac II keyboards).
3. (Obsolete PDP-10; often "ALT") An alternate name for the ASCII ESC character (Escape, ASCII 27), after the keycap labelling on some older terminals; also "altmode" (/awlt'mohd/). This character was almost never pronounced "escape" on an ITS system, in TECO or under TOPS-10, always alt, as in "Type alt alt to end a TECO command" or "alt-U onto the system" (for "log onto the [ITS] system"). This usage probably arose because alt is easier to say.