Answer

If you mean Nandyāvarta (often spoken as “nandavart” or “nandavrat”), it is a Jain auspicious symbol, not a vow. It is a diagram shaped like an elaborate swastika or labyrinth and is counted among the eight auspicious symbols (aṣṭa-maṅgala) in Jainism. ( jainpedia.org)

Explanation

In Jain tradition, Nandyāvarta is considered a symbol of joy and prosperity. It is often drawn in puja and temple rituals, and Jain sources describe it as having nine branches, sometimes linked with the nine treasures of a universal monarch. ( jainpedia.org)

Spiritual Understanding

The symbol reminds a Jain devotee of auspiciousness, inner harmony, and the sacred order of life. Because it appears in worship and religious art, it helps focus the mind on devotion and respect for the Tirthankaras. ( jainpedia.org)

Takeaway

So, in Jain Dharma, Nandavarta/Nandyāvarta = an auspicious sacred symbol used in worship. If you meant a different Jain term, it may be spelled slightly differently. ( jainpedia.org)