Agenderlessness: an unifying term for people who are at least agender or genderless. 

The terms could be synonymous or interchangeable to each other. If you identify as both, you could name that as agxndxr, gxndxrless, gxnderless, agxnder, gxndxrlxss.

Concept from nonbinary flag black. Not necessarily encompassing the whole agin spectrum. ~ Ap