As a verb, transitive and intransitive: to be or act miserly, often in a tricky fashion. As an exclamation, an expression of happy success in such activity. As a noun: (1) a good deal; (2) a person who lives by steining.
"I was walking through the lobby when I saw a buffet set up for some conference, so I steined some breakfast there."
"I gave her a 10, but she gave me back change for a 20. Stein!"
"Charles Shaw is only $2 a bottle at Trader Joe's. It's a total stein."
"He never brings anything to a party--what a stein."