Beyond the known, expected or predictable.
Budget-setting: "Aw, c'mon, stick to the facts, man. That's an outside guess."
Re an oddball- & yeah, I've heard it more than said it: "THAT thinkin's a little outside,eh?"
Re acts-a-Gawd: Wow! See that one!? That came from outside, dinnit!"
Means definitely OFF in some fashion, & probably off yr. rocker.
Think it's Rom, from down the Lake in Nonantum, Newton, Massachusetts.
moosh" means "crrazy guy"
Whaddya, you divvya
!? You quit that job?