adjective, nominative singular or accusative singular neuter + enclitic api
Analysis. tadubhaya (tad- + ubhaya, 'that + both') + api ('also, even'), yielding 'both of those things even' or simply 'both of those'; the -m in surface form tadubhayaṃ is the accusative neuter singular marker before api.
Etymology. tad- from demonstrative pronoun ta- (Sanskrit tat, Latin iste, English that); ubhaya 'both' from Indic ubhau (Sanskrit ubhau), cognate with Greek ampho- and Latin ambo (both). The compound tad-ubhaya literally 'that-both' denotes 'both of those' by treating the pair as a single referent.
Meanings from the Digital Pāḷi Dictionary; morphology and etymology by Claude.
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