Here are some possibilities for what you might have meant:
* "Terrestrial": This refers to something related to the Earth or its inhabitants.
* "Territory": This refers to an area of land under the control of a particular government or person.
* "Serenity": This refers to a state of calmness, peacefulness, and tranquility.
* "Verity": This refers to truth or accuracy.
If you can provide more context about how you encountered the word "tererity", I might be able to help you figure out what it was meant to be.