expressibility 

The ability for a certain subject to express themselves.

I wanted to have a certain expressibility in my paper, but the word expressibility isnt defined anywhere...well it is now.

expressibility by DO.g March 7, 2004

Expressificity 

When a black person takes the time to choose a fancy word before speaking

Reginald used extreme Expressificity when speaking at the all black college.

Expressificity by clickeye3 December 9, 2019