To smoke the herb...marijuana. But the word should only be used to indicate that you plan on smoking when you are within hearing distance of an anti-smoker. The idea is to keep your pot smoking identity secret by using sneaky terms.
(you're talking on the phone with a friend and you're mom is in the kitchen nearby)
You: Hey wats up bro...got any plans for today?
Friend: Actually, I'm bored out of my skull...what could we do to kill some time?
You: Well, we could sherb.
Friend: ahhhhhhh...now there's an idea
Sound used to imitate a penguin.
Can be used in any situation to call for attention or to break the awkwardness.
Can also be used to express feelings or affection depending on the tone.