1. Any act in which a person or persons get screwed over without their knowledge or consent. The victim, not for a lack of knowlegde is played and are generally unaware of the fact that they have been screwed over. The act is usually accompanied by the 'gibber' throwing up their hands and a)laughing or b)saying something to the effect of "Fuck it, I'm out" when the gibbing is revealed.
(2.a) gib (noun)
A small metal or wooden wedge used for keeping a machine part in place.
(2.b)(gibbed, gibbing) verb
To secure with a gib.
(2) That machine was shaking quite a bit, but its better now that its been gibbed.