ascender vs mounter

ascender and mounter both are nouns.

Word	Noun	Adjective	Verb	Adverb
ascender	Yes	No	No	No
mounter	Yes	No	No	No

As nouns, mounter is a hyponym of ascender; that is, mounter is a word with a more specific, narrower meaning than ascender:

Other hyponyms of ascender include climber.

ascender (noun)	mounter (noun)
(printing) the part of tall lowercase letters that extends above the other lowercase letters	someone who ascends on foot
a lowercase letter that has a part extending above other lowercase letters	a skilled worker who mounts pictures or jewels etc.
someone who ascends