Tethrennon

The tethrennon is equal to E100#^^#^#9 = E100#^^#########100 in Extended Cascading-E Notation. The term was coined by Sbiis Saibian.

Etymology
The name of this number is based on the number tethrathoth and the root "xennon" from "polyxennon". Polyxennon is the name for a 10-dimensional figure and 10-D figures are constructed from multiple 9-D figures (hence the "poly"), so a "xennon" can be considered a 9-dimensional figure.