An exremely lame joke or quip that when said is followed by silence from everyone around you, not uncommonly followed by blank stares or looks of disbelief. When a zoid is uttered it is customary for one of the zoiders freinds or aquantinces to point this out by saying "zoid". You are only allowed three in an evening. The results of the third zoid is that the zoided party may not speak the rest of the night. It is rare that a third zoid is achieved but it can be done by the less witty, and humorless of us.If it is achieved,the party that is not to talk must be silent, if caught talking there should be repercussions. These can vary.
You are at a nightclub with your freinds and a fine girl walks by with some large breasts. One of your less than debonair freinds complements her by saying "Hey why dont you and your two freinds join us for a drink." After she backhands him and throws her drink in his face, You reply "Zoid , two more and you can't talk the rest of the night ."While shaking your head in dissaproval.