What is the meaning of Sabbat?

Witches' Sabbath.

Sabbath

Sabbath, biblical seventh day

witches' Sabbath, meeting of witches at midnight

noisy meeting

to bang, thump, stamp

witches' Sabbath

Sabbath, the Biblical seventh day of the week, observed as a day of rest in Judaism

Sabbath (as above)

alternative form of sabá

Sabbath (Biblical seventh day of the week, observed in Judaism and by some Christians)

Sabbath (Sunday, observed by the majority of Christians)

supine of sabba

Source: wiktionary.org