Terotetremar

Terotetremar is equal to \(f_{\psi(M\uparrow\uparrow 10^{12})}(10)\). The term was coined by Denis Maksudov

Etymology
The 3 parts of the name, "tero", "tetr" and "emar", mean \(1\ \text{trillion}\), the "in-" operation. So the full name indicates the ordinal index of the number.