ascender
Concise Oxford English Dictionary © 2008 Oxford University Press:
ascender/əˈsɛndə/
▶noun
- 1 a person or thing that ascends.
- 2 a lower-case letter (or part of it) that extends above the level of the top of an x (such as b and f).
- 3 Climbing a device which can be clipped to a rope to act as a foothold or handhold.
'ascender' also found in these Oxford entries:

