verb (used with object), back·stabbed, back·stab·bing.to attempt to discredit (a person) by underhanded means, as innuendo, accusation, or the like.
On a side-note, not all people who seem like backstabbers are bad people, or backstabbers at all. One of my favorite stories/movie is Hercules. Meg, the supporting actress character supposedly lives for her own benefit. I love how at first she couldn't have cared less about Hercules but then gains his trust only to lose it again when Hades is unhappy with her work ability. There are two backstabbers in this story line. The perceived backstabber, who in this case is Meg and the actual backstabber, Hades lord of the Dead. Hades leaves Meg for dead in that giant pool of lost/damned souls even after all her hard work. Meg was claimed to be a backstabber by first timers watching the movie for the first time because of how she caused Hercules to lose all his power (not to mention TRUST in her.). In the end though there is a happy ending and Meg comes out victorious in love but for awhile, Phil, Hercules's satyr mentor, didn't believe her goodness. I liked Meg because she was obviously heavily conflicted about tricking Hercules.I'm glad she chose to deny Hades.