Any show, movie, etc., where the majority of the lead roles are played by big-name actors. They don't have to be A list. B, C, and even D will do, although in that case, relying on their talents is preferable to relying on their names. If the character list is really big, this can spill over into supporting roles as well.
In the days of the studio system, this was easy to do, but once actors' salaries started rising — which coincided with major advances in visual effects technology, meaning that the effects, rather than the cast, soon became the most expensive part of a film's production — this practice gradually declined. Compare the casts at the beginning of the Disaster Movie Era with those at the end of it.
These days, you'd either need a lot of money to pull this off, convince the actors that this is just a fun breather film or be willing to settle for loads of cameos. The exception is animated films, where stars are willing to get paid a lot less just to do voice work and the logistics and scheduling are easier.
All Star Cast has been suggested to play 5 roles. Click below to see other actors suggested for each role, and vote for who you think would play the role best.