neuter accusative singular (or error for majjheka-); surface form shows contamination or scribal variation
Analysis. majjhe (locative of majjha, 'middle') + kalyāṇaṁ (neuter accusative of kalyāṇa, 'beautiful, wholesome, auspicious'). The phrase denotes the doctrine of the middle way as taught by the Buddha—avoidance of extremes (sensual indulgence and self-mortification). In compound formation, 'middle' (majjha-) qualifies the 'wholesome' or 'beautiful' (kalyāṇa-).
Etymology. majjha derives from PIE *medhyo- (middle); cognates include Sanskrit madhya, Latin medius, English mid. kalyāṇaṁ from a root meaning 'to call out, invoke' (whence 'well-called', hence 'excellent'): see Sanskrit kalyāṇa.
Meanings from the Digital Pāḷi Dictionary; morphology and etymology by Claude.
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