Getting the chop

I'd rather get the sack than the chop.

Some euphemisms for being guillotined:

Looking thorugh the little window

Kissing the sharp-tongued woman.

The guillotine was much more humaine than either of the most common forms of execution:

For common criminals: The short drop in which the criminal was knocked off a stool to dangle and dance.

For royalty/ nobles: beheading with an ax. The axeman sometimes did not cut cleanly on the first chop. Much to be preferred was the "French swordsman"

It is said that Louis XVI's necks was so thick that it took guillotine drops to kill him.