Cons cell is a term that is used in computer science to describe the basic building block of a functional programming language. It is short for "constructor cell", and it refers to a data structure that is used to construct other data structures. Synonyms for cons cell include "list cell", "pair cell", "cell", and "node". These terms all describe the same fundamental data structure that is used in functional programming languages. The cons cell is a key concept in functional programming, and understanding its role is essential to understanding how functional programming languages work.