Billilogue is a base googolism of the second order Hyper-L notation invented by Googology Wiki user JTOnstead20. It is defined as \(L((9))\) in the notation. This means the following: Take the reverse Log function of 9 to get a billion. Then use the double parenthesis to build a power tower starting with \(10^{bill^{bill^{...}}}\) and going a billion units high. This is roughly equivalent to \(Billion\uparrow\uparrow Billion\) in arrow notation.