
1) Computer key 2) How some shortcuts start 3) Space bar neighbor, at times
Found on
https://www.crosswordclues.com/clue/alt-key

The standardized keyboard symbol for the Alt key (which may be used when the usual Latin lettering `Alt” is not preferred for labelling the key) is given in ISO/IEC 9995-7 as symbol 25, and in ISO 7000 `Graphical symbols for use on equipment” as symbol ISO-7000-2105. This symbol is encoded in Unicode as U+2387 alternative key symbol (⎇)....
Found on
http://en.wikipedia.org/wiki/Alt_key
No exact match found.