pushdown

From push +‎ down; by analogy with a spring-loaded stack of plates in a cafeteria.

pushdown (not comparable)

1. (computing) Describing a stack in which items are removed in a LIFO manner from the end at which they were added.

pushdown (plural pushdowns)

1. A pushdown automaton.
   • 2003, Wilfried Brauer, Hartmut Ehrig, Juhani Karhumäki, Formal and Natural Computing: Essays:

     Since indexed grammars are context-free grammars with pushdowns, the generalization of Thatcher's result shows that they generate the yields of the tree languages recognized by deterministic pushdown tree automata.

Deverbal from push down.

pushdown (plural pushdowns)

1. (bodybuilding) An exercise that requires one to push weight downward.
   • (Can we date this quote?), Greg Merritt, “Go Beyond Failure with Dropsets”, in Muscle & Fitness‎^[1]:

     Machine exercises with weight stacks, like pushdowns or pulldowns, are ideal for cranking out more than three drops because all you need to do is insert the pin in a higher (lighter) slot each time.