In transitive terms the difference between grab and trap
is that
grab is to grip suddenly; to seize; to clutch while
trap is to provide with a trap.
In intransitive terms the difference between grab and trap
is that
grab is to make a sudden grasping or clutching motion (at something) while
trap is to leave suddenly, to flee.
In lang=en terms the difference between grab and trap
is that
grab is a soundbite while
trap is cubicle (in a public toilet.