Matteyya & metteyya
(adj.) reverential towards one’s mother, mother-loving DN.iii.74; Pv.ii.7#18 (= mātu hita Pv-a.104 variant reading mett˚). Spelling at DN.iii.72 is metteyya. It is difficult to decide about correct spelling, as metteyya is no doubt influenced by the foll. petteyya, with which it is always combined.
fr. mātā, *mātreyya → *matteyya