To "Smash and Pass" is the process of meeting another person for the intent of having sex with. Soon after finishing, both people leave; usually to never talk again. The sole purpose of doing this is to try something new and achieve extreme pleasure while doing so for both partners.
A one night stand is the same meaning as Smashing and Passing but is the more popular of the definitions.
"The other night I met this chick over the internet. She wasn't amazingly hot but she was good enough to smash and pass."