Packed out

(of a place) very crowded.

"The concert venue was packed out, with every seat filled and people standing shoulder to shoulder in anticipation of the show."
(The sentence uses the word "packed out" to describe the venue as being very crowded without defining the word explicitly.)

Packed out

(of a large number of people) crowd into and fill.

"hundreds of people packed out the venue"

Packed Out

is Los Angeles prison gang slang. Its short for getting "rat packed", that is, jumped and beat up.
.

Yea - me, BoBo, Cockpit and Sliprod Packed Out that fool Neckbone yesterday. He know not to step foot round here anymore

Pack out

carry something away rather than leaving it behind (used especially with respect to refuse at remote campsites).

"pack out any garbage you have left"