alt

Short definition from Wiktionary

Noun

1. 1
   Of a voice or instrument, high pitch; especially, the octave above the top line of the treble stave.
2. 2
   A state of excitement, a heightened emotional condition.
3. 3
   Clipping of altitude.
4. 4
   An alternate or secondary character.
5. 5
   An alternate account.
6. 6
   An alternative investment or alternative fund.
7. 7
   An alternate version of a piece of art, especially without much changes beyond a specific thing.
8. 8
   Ellipsis of alt text.
9. 9
   Synonym of altbier.
10. 10
    A modifier key used to change (alternate) the function of other pressed keys.
11. 11
    Initialism of alanine transaminase.

Adjective

1. 1
   Clipping of alternate.
2. 2
   Clipping of alternative, especially as a cultural phenomenon seen as being outside the mainstream of its genre.

Proper noun

1. 1
   A river in West Lancashire and Merseyside, England that flows into the Irish Sea; in full, the River Alt.