The meaning of the word "Sabbat" used in Judaism and Paganism are same or different?

First off, they're spelled differently... they also have different roots. Sabbat is French rooted in Latin while, Shabbat is Hebrew.

sabbat
1: WITCHES' SABBATH
2: any of eight neo-pagan religious festivals commemorating phases of the changing seasons

History and Etymology for sabbat
French, literally, sabbath, from Latin sabbatum

https://www.merriam-webster.com/dictionary/sabbat

Shabbat
1: the Jewish Sabbath

History and Etymology for Shabbat
Hebrew shabbath

https://www.merriam-webster.com/dictionary/Shabbat

The origin of both terms is the Hebrew "Shabbat", also rendered "Shabbas". The Hebrew means "he rested", referring to God resting on the seventh day after his six days of labor on Creation.
"Sabbat" is taken directly from the French, which descends from the Hebrew through Greek and then Latin.
Functionally, the observations are as different as one would imagine. The Hebrew Shabbat is a weekly observance of enforced rest and worship of the one God. The Pagan Sabbat is one of four or eight (depending on the traditions followed) observations over the course of the year tied to the lunar and solar cycles (four each) related to several deities and natural occurrences.