Gatherings where several Guide units got together for a joint event, usually featuring games, challenges, and a closing ceremony, were known as Rallies.
Brownies too, had get-togethers, and traditionally, they were known as Brownie Revels. The units would usually gather at a field or park, and there would be games, crafts and activities for the units to rotate round, usually based on a theme. The closing event would usually be a sing-song with all the units joining together, before it was time to head home.
The term was dropped in the 1990s - as the name was not familiar to Brownies, being more associated with a chocolate brand than with it's original meaning!