A garbage compactor (or trash compactor) was a chamber used to store and compress refuse. The walls would come together and compress and crush the garbage. The doors to the compactors were usually magsealed.
The garbage compactor that Tallest ZIM, Queen Gazlene, GIR and Turoan Princes Banakida fell into aboard the Mega-Massive, Garbage Compactor 32638987, was under the category of recyclable waste.
They were attacked by a splorch worm-squid, which were known to live in garbage compactors. The princess was almost killed when the worm-squid took her underwater.