ordinal number + api (sandhi form tatiyampi); neuter nominative/accusative
Analysis. tatiyaṃ (neuter accusative singular of tatiya, 'third') + api ('also, even, too') — fused by sandhi into tatiyampi. The accusative adverbializes the ordinal: 'in the third instance', hence 'for the third time'.
Etymology. tatiya derives from ta- (the oblique stem of ta, the demonstrative 'that') + the ordinal suffix -iya (cognate with Latin -arius and Greek -ios, denoting order or rank). The base ta- is proto-Indo-European *to-, the same root as English 'the' and 'that'; the ordinal-forming suffix -iya shapes abstract numerical place.
Meanings from the Digital Pāḷi Dictionary; morphology and etymology by Claude.
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