High pitch, of a voice or instrument; especially, the octave above the top line of the treble stave.
"Press and hold the Alt key while typing a shortcut to open the file menu instead of just pressing F10."
Abbreviation of altitude.
A modifier key used to change (alternate) the function of other pressed keys.
In plain English: An alt is someone who has different interests, tastes, or beliefs than most people around them.
"The alt on my phone is ringing loudly while I try to find a quiet place for a call."
Usage: Use this term only in specific musical contexts to describe a high-pitched tone an octave above the standard staff range. Avoid using it for general descriptions of loudness or volume outside of music theory discussions.
Abbreviation of alternate.
"The alt account was created to share posts that didn't fit on the main profile."
In plain English: Alt means something that is different from what most people do, think, or wear.
"We looked at the alt accounts for more information on the topic."
The word "alt" comes from the Latin altus, which means "high." It entered English as a doublet alongside the words "old" and "alto," sharing that same original sense of height or elevation.