Alice definition

French and English contraction of Old High German Adalheidis; from adal "noble" + heid "sort, kind".

popular in England since Middle Ages.
The main character in Lewis Carroll's books Alice's Adventures in Wonderland and Through the Looking-Glass.
In various fields such as cryptography and physics, a conventional name for the person or system that sends a message to another person or system conventionally known as Bob.

1380s-1390s, Geoffrey Chaucer, The Canterbury Tales: The Wife of Bath's Prologue and Tale:

That Iankin clerk, and my gossib dame Alis, / And I my-self, in-to the feldes wente.
1871 Lewis Carroll, Through the Looking Glass, and What Alice Found There, Chapter 6:

"My name is Alice, but - "

"It's a stupid name enough!" Humpty Dumpty interrupted impatiently. "What does it mean?"

"Must a name mean something?" Alice asked doubtfully.

"Of course it must," Humpty Dumpty said with a short laugh, "my name means the shape I am - and a good handsome shape it is, too. With a name like yours, you might be any shape, almost."
1968 Kurt Vonnegut, Welcome to the Monkey House, Delacorte Press, page xiv:

She was heavenly to look at, and graceful, both in and out of water. She was a sculptress. She was christened 'Alice', but she used to deny that she was really an Alice. I agreed. Everybody agreed. Sometime in a dream maybe I will find out what her real name was.