NOUN (3)

1. someone who ascends;

2. a lowercase letter that has a part extending above other lowercase letters;

3. (printing) the part of tall lowercase letters that extends above the other lowercase letters;

WordNet (r) 3.0 (2006):

ascender
    n 1: someone who ascends
    2: a lowercase letter that has a part extending above other
       lowercase letters
    3: (printing) the part of tall lowercase letters that extends
       above the other lowercase letters

The Free On-line Dictionary of Computing (30 December 2018):

ascender

    A lowercase letter that extends above the "x-height"
   (the height of the letter "x"), such as "d", "t", or "h".
   Also used to denote the part of the letter extending above the
   x-height.

   Compare descender.

   (1998-03-27)