Declension table of ?upaca

Masculine	Singular	Dual	Plural
Nominative	upacaḥ	upacau	upacāḥ
Vocative	upaca	upacau	upacāḥ
Accusative	upacam	upacau	upacān
Instrumental	upacena	upacābhyām	upacaiḥ upacebhiḥ
Dative	upacāya	upacābhyām	upacebhyaḥ
Ablative	upacāt	upacābhyām	upacebhyaḥ
Genitive	upacasya	upacayoḥ	upacānām
Locative	upace	upacayoḥ	upaceṣu

Compound upaca -

Adverb -upacam -upacāt