שולחן ערוך יורה דעה · סימן ר״ז

English

Synonyms for vows are like vows. How so? If one said "Konam", "Konach" or "Konas" is this loaf of bread to me, it is forbidden [as if one said "Korban", sacrifice]. In every place, one follows local terminology, and if there is a local phrase for a vow, it is truly a vow. RAMA: So too, if one does not understand the language of the Rabbis and uses them for a vow, it is invalid. But synonyms of synonyms, or a word that sounds very distant from the language of a vow, is not a vow. RAMA: And a vow can be made in any language where forbidding something to oneself is called 'vow'.