A shotgun with a barrel and sometimes buttstock which have been shortened by sawing them off; a sawed-off shotgun.
Shortened by sawing.
The sawed-off shotgun was illegal because its shorter barrel made it too easy to conceal.
Short (as though something that should be there isn't).
He was a sawed-off runt, just a little guy, but he packed so much attitude into that little package that no one was going to make anything about it.