River in Devon (3)
I believe the answer is:
exe
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">river in devon</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 exe that I've seen before include "Tiverton's river" , "River in SW UK" , "English river sounds like a letter" , "River of southwest England" , "River of SW England" .)