Pop: /pop/ [from The Operation That Removes The Top Of A Stack,
And The Fact That Procedure Return Addresses Are Usually Saved On
The Stack] (also Capitalized `POP') 1.
:pop: /pop/ [from the operation that removes the top of a stack,
and the fact that procedure return addresses are usually saved on
the stack] (also capitalized `POP') 1. vt. To remove something from
a {stack} or {pdl}. If a person says he/she has popped
something from his stack, that means he/she has finally finished
working on it and can now remove it from the list of things hanging
overhead. 2. When a discussion gets to a level of detail so deep
that the main point of the discussion is being lost, someone will
shout "Pop!", meaning "Get back up to a higher level!" The
shout is frequently accompanied by an upthrust arm with a finger
pointing to the ceiling.
-- The AI Hackers Dictionary