ascenderPronunciation: /əˈsɛndə/Definition of ascender noun 1a part of a letter that extends above the level of the top of an x (as in b and f). a letter having an ascender. 2 Climbing a device which can be clipped to a rope to act as a foothold or handhold, or to keep something in position. ascender in other Oxford dictionaries Definition of ascender in the US English dictionary