If you whip the pants off someone, you whip them until you wear the pants away -- in other words, you really beat them up.
"Write it off" means to dismiss something.
To laugh allot
The meaning of the idiom "to slap the back off you" is fairly straightforward. It implies an exaggeration, that one would slap someone else so hard that their back would come off.
Can you figure out the meaning by defining the terms literally? No, so it is an idiom. Literally, it means to remove something, but figuratively it means for an airplane to get off the ground.
Showing off, being well dressed and flashy.
Nothing. To get off the hook, however, means to escape punishment.
It means being ticked off, or very mad.
Old sailing slang meaning to be no longer in danger.
To lose ones temper and react violently.
Ants in the pants means that someone can't sit still. Imagine if they actually had ants crawling around inside their pants! You might also say someone was bouncing off the walls, or couldn't sit still.
Something that can happen really fast or in the "blink of an eye"
That usually pertains to a weapon discharging when you don't want it to.