Gender: Feminine
Origin: Estonian
Meaning: “counterpart; double.”
(TAY-see)

The name is often used as an alternative for Theresa but can also possibly be derived from the Estonian, teisik, meaning “double; counterpart.”

The designated name-day is April 26.

Sources

1. http://www.behindthename.com/namedays/lists/est.php
2. http://aare.pri.ee/dictionary.html?query=teisi&lang=ee&meth=part&switch=en&otsi=search