Seemingly endless (12)
(Other definitions for interminable that I've seen before include "Tedious" , "Without end" , "Long drawn-out" , "Seeming likely to go on for ever" , "Endless" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">seemingly endless</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 vast that I've seen before include "Unusually great" , "Astronomical" , "Huge, enormous" , "Boundless" , "Extremely large or extensive" .)