adverb; contraction of taya + idaṁ (instrumental of taya 'three' + neuter nominative/accusative singular of idaṁ 'this')
Analysis. taya (instrumental of ti 'three') + idaṁ (this). The contraction expresses 'by means of these three' or 'in respect of these three things'.
Meanings from the Digital Pāḷi Dictionary; morphology and etymology by Claude.
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