Critical Mass – Learn the Lingo
(source : Facebook – I won’t post links to sites that require logging in and commerce with your details in the process)
These words are used at some Critical Mass events:-

Bike-lifting (Also known in Chicago as the Chicago hold-up)- is when a participant raises his or her bicycle in the air. This occurs when an intersection is corked, when a cyclone is occurring, or at any point a participant desires to hold a bicycle in the air.

Corking- Corking is a tactic used to prevent traffic from entering the path of the cyclists.

Cyclone Cyclones- form when the mass begins to circle an intersection. Popular in Chicago’s large six-point intersections, cyclones can be used to “mass up” the critical mass, so that it can maintain the density of cyclists necessary to prevent the flow of automotive traffic. The tactic also allows splinter masses time to rejoin the group.

Die-in Die-ins- are when participants lay down on the ground with their bikes to symbolize cyclist deaths and injuries caused by automobiles, very popular in Montreal.

“Mass up” or “Mass it up”- In the middle or at the end of the group of
cyclists, the number of cyclists traveling on the road can grow thin, resulting in dangerous conditions for riders if automotive traffic attempts to cut through the middle of the mass while cyclists are still passing. Participants in some cities will yell “mass up” or “mass it up in order to tell the front of the group to slow down. Different tactics are used to mass up such as simply slowing down or stopping as well as cycloning.

Splinter mass- Splinter masses are a common occurrence due to the unorganized nature of the event. A splinter mass occurs when a smaller group of the larger critical mass separates from the main mass inadvertently. They often no longer possess a mass that is “critical enough to stop traffic. “Massing up” allows splinter masses to rejoin the group.