Variable (2,3,4)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">variable</span>' is the definition.<br/ ><span class="explanation-format__explanation">(parameter can mean a variable or value)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for parameter that I've seen before include "Limitation" , "Factor defining limits" , "Limiting factor" , "Quantifiable characteristic of a system" , "One of a set of factors as conditions for operation of a system" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">variable</span>' is the definition.<br/ ><span class="explanation-format__explanation">(similar in meaning)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Another definition for changeful that I've seen is " Fluid".)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">variable</span>' is the definition.<br/ ><span class="explanation-format__explanation">(unknown is a kind of variable)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for unknown that I've seen before include "Not recognised by anyone" , "Unidentified - not explored" , "Strange - obscure" , "Not recognized" , "Quite obscure - like x" .)
(Other definitions for up and down that I've seen before include "situations for ten thousand and one men" , "Directions taken by mountaineers" , "choices from the mezzanine?" , "To and fro" , "crinkled?" .)