Fast
Fasting was a period during which one gave up food and usually most beverages other than water. It was often done (in many cases for religious reasons) to remind oneself of how fortunate one was.

Borothans were known to fast leading up to viewing the Great Plume of Agosoria. ()

In 2268, Garth of Izar explained to James T. Kirk and Spock that Governor Cory would not be eating with them, explaining he was fasting. ()

The Bajoran Time of Cleansing was a month-long occasion in the Bajoran religion during which the people of Bajor fasted. ()

Additionally, Bajorans fasted to commemorate Ha'mara, or the arrival of the Emissary of the Prophets (Benjamin Sisko). ()

In Klingon mating rituals, before his wedding, the groom went on the road to Kal'Hyah, a period of fasting and rigorous physical challenges, with his closest friends. ()

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Mythology
Ceremonies
Victual culture