Could you please double-check the spelling or provide more context about where you encountered this term?
Perhaps you meant:
* Celotvy (misspelling of "Celotvy" which is a name found on the internet)
* Celestial Body (a natural object in space such as a star, planet, moon, etc.)
* Ceilometry (the measurement of cloud heights)
Please let me know, and I'll do my best to help you further!