##  [Pushdown Automaton](/pushdown-automaton) 

  ##  [Pushdown Automaton](https://natural.quantumdictionary.io/pushdown-automaton-0) 

  

 [![Natural & Formal Sciences Dictionary](/sites/default/files/styles/large/public/2026-01/Natural%20%26%20Formal%20Sciences.png.webp?itok=2kCDRVQv)](/topic-specific-dictionaries/natural-formal-sciences)



**Natural & Formal Sciences Dictionary**

 







 

 

 

 



 

 

 

 

Definition

An automaton augmented with a last-in, first-out stack used as unbounded auxiliary memory; it recognizes exactly the languages that can be generated by context-free grammars (context-free languages) by applying state transitions together with push and pop operations on the stack.