The terms "Cosmic Efficacy" and "Tithonicity" are not standard scientific or philosophical terms. They are not commonly used in any established academic discipline.

It's possible these terms are:

* Neologisms: New words coined by someone, potentially for a specific purpose or within a specific context. Without more context, it's impossible to know their intended meaning.

* Misspellings: Perhaps you're thinking of other terms related to cosmology or physics, and the words are slightly misremembered.

* Fictional concepts: Maybe these terms appear in a book, movie, or other fictional work.

To help me understand what you're looking for, please provide me with more information:

* Where did you encounter these terms? (A book, website, conversation, etc.)

* What context were they used in?

* What do you think they might mean?

With more information, I can better understand what you're asking and potentially offer a more accurate answer.