ascender

/AH0 S EH1 N D ER0/
noun
  1. 1

    A person or thing that ascends.

  2. 2

    (graphology) The portion of a lowercase letter that extends above the midline.

  3. 3

    A mechanical device used for ascending on a rope; ascendeur.

Source: https://en.wiktionary.org/wiki/ascender