Declension table of ?vivatsa

Neuter	Singular	Dual	Plural
Nominative	vivatsam	vivatse	vivatsāni
Vocative	vivatsa	vivatse	vivatsāni
Accusative	vivatsam	vivatse	vivatsāni
Instrumental	vivatsena	vivatsābhyām	vivatsaiḥ
Dative	vivatsāya	vivatsābhyām	vivatsebhyaḥ
Ablative	vivatsāt	vivatsābhyām	vivatsebhyaḥ
Genitive	vivatsasya	vivatsayoḥ	vivatsānām
Locative	vivatse	vivatsayoḥ	vivatseṣu

Compound vivatsa -

Adverb -vivatsam -vivatsāt