look up any word, like the eiffel tower:
Looking Slack-Jawed At My Monitor. Incredulity at what one is seeing or reading on the Internet.
As a statement:
I was on 4chan and I was all LSJAMM.

As a response:
Biff: I just had sex with my mother.

About someone else:
That Russian kid seeing porn for the first time was totally LSJAMM.

In Meatspace:
Guy #1: Dude, check the hottie.
Guy #2: El-es-jam for sure
by BRB-123 January 20, 2011