wall (interj.)

[WPI]

1. An indication of confusion, usually spoken with a quizzical tone:

Wall??

2. A request for further explication. Compare octal forty.

3. [Unix, from ‘write all’] v. To send a message to everyone currently logged in, esp. with the wall 8 utility. It is said that sense 1 came from the idiom ‘like talking to a blank wall’. It was originally used in situations where, after you had carefully answered a question, the questioner stared at you blankly, clearly having understood nothing that was explained. You would then throw out a

Hello, wall?

to elicit some sort of response from the questioner. Later, confused questioners began voicing

Wall?

themselves.