Inner (8)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">inner</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that inner can be written as internal)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for internal that I've seen before include "Interior" , "Domestic" , "In-house - private" , "Cause of engine power" , "Inside the body" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">inner</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I know that inner can be written as interior)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for interior that I've seen before include "Inland part of a country" , "Inner; inland" , "Inside of a building" , "upcountry" , "Domestic" .)
(Other definitions for tube that I've seen before include "Hollow cylindrical object" , "appearing tinny?" , "channel" , "Hollow body for the underground" , "Pipe (with trains?)" .)