Declension table of ?dvayin

Masculine	Singular	Dual	Plural
Nominative	dvayī	dvayinau	dvayinaḥ
Vocative	dvayin	dvayinau	dvayinaḥ
Accusative	dvayinam	dvayinau	dvayinaḥ
Instrumental	dvayinā	dvayibhyām	dvayibhiḥ
Dative	dvayine	dvayibhyām	dvayibhyaḥ
Ablative	dvayinaḥ	dvayibhyām	dvayibhyaḥ
Genitive	dvayinaḥ	dvayinoḥ	dvayinām
Locative	dvayini	dvayinoḥ	dvayiṣu

Compound dvayi -

Adverb -dvayi