A machine that accepts used (empty) beverage containers and returns money to the user, as part of a recycling initiative.

plural of reverse vending machine

(very rare) Alternative form of forward time machine

plural of forwards time machine

plural of backwards time machine

(rare) Alternative form of backwards time machine

(science fiction) A time machine that can only allow travel to the past, but cannot also allow travel to the future.

plural of forward time machine

plural of backward time machine

(science fiction) A time machine that can only allow travel to the future, but cannot also allow travel to the past.