Declension table of ?tathyavacana

Neuter	Singular	Dual	Plural
Nominative	tathyavacanam	tathyavacane	tathyavacanāni
Vocative	tathyavacana	tathyavacane	tathyavacanāni
Accusative	tathyavacanam	tathyavacane	tathyavacanāni
Instrumental	tathyavacanena	tathyavacanābhyām	tathyavacanaiḥ
Dative	tathyavacanāya	tathyavacanābhyām	tathyavacanebhyaḥ
Ablative	tathyavacanāt	tathyavacanābhyām	tathyavacanebhyaḥ
Genitive	tathyavacanasya	tathyavacanayoḥ	tathyavacanānām
Locative	tathyavacane	tathyavacanayoḥ	tathyavacaneṣu

Compound tathyavacana -

Adverb -tathyavacanam -tathyavacanāt