Protean
Part of speech: adjective
Definition: Exceedingly variable; readily assuming different shapes or forms. Of or pertaining to Proteus; characteristic of Proteus.
Variable
Part of speech: noun
Definition: something that is variablesomething whose value may be dictated or discovereda quantity that may assume any one of a set of valuesa symbol representing a variablea named memory location in which a program can store intermediate results and from which it can read thema variable star
Part of speech: adjective
Definition: able to varylikely to varymarked by diversity or differencehaving no fixed quantitative valuetending to deviate from a normal or recognized type
Example sentence: If there are four equations and only three variables, and no one of the equations is derivable from the others by algebraic manipulation then there is another variable missing.