A Di Đà

Etymology
, from. While the consonant of  was, it was palatalized before a following high vowel, and the palatalized  was fortited into what is now spelt as d. A similar fortition occurred for the palatalized which was fortited as a t(h) sound. seems to be a hypercorrected or etymologically motivated form which attempts to render the original. Compare 🇨🇬 and 🇨🇬.

Usage notes
As a regular Sino-Vietnamese term that happens to be Buddhist, the unhyphenated spelling is to be expected, since hyphenation is now only reserved for non-Sino-Vietnamese transcriptions. The conservative hyphenated spelling is enforced rather inconsistently even in Buddhist writings.