1. An acronym that stands for Portable Jack Off Station. This term refers to using a laptop computer for the sole purpose of downloading and jacking off to porn where ever one travels. PJOS is pronounced "Pee-Joss"
2. The acronym can also stand for Pocket Jack Off Station if the electronic device being used for pornographic satisfaction can be fit into one's pocket. Such devices include cell phones and PDAs.
"I went out of town without my girlfriend, but stayed busy with my PJOS"
"Because my job is really boring, I pack my PJOS with me and take many bathroom breaks"