Complete extent (4)
(Other definitions for span that I've seen before include "Arch across" , "Distance between two points in time or place" , "Measurement between tips of thumb, little finger" , "Distance or interval between two points" , "Bridge made of pans" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">complete extent</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for gamut that I've seen before include "Whole range (from A to Z)" , "Complete extent or range" , "Compass, scale" , "Complete range (of something)" , "Full range, compass" .)