Declension table of ?apitṛ

Masculine	Singular	Dual	Plural
Nominative	apitā	apitārau	apitāraḥ
Vocative	apitaḥ	apitārau	apitāraḥ
Accusative	apitāram	apitārau	apitṝn
Instrumental	apitrā	apitṛbhyām	apitṛbhiḥ
Dative	apitre	apitṛbhyām	apitṛbhyaḥ
Ablative	apituḥ	apitṛbhyām	apitṛbhyaḥ
Genitive	apituḥ	apitroḥ	apitṝṇām
Locative	apitari	apitroḥ	apitṛṣu

Compound apitṛ -

Adverb -apitṛ