Line on a letter (5)
I believe the answer is:
serif
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">line on a letter</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 serif that I've seen before include "Slight projection finishing off printed letter - puts fires out" , "decorative line" , "Stroke's foot" , "Little bit of character" , "Short line at the end of the main strokes of a printed character" .)