遐爾 = hiah'niq = so, such a, to such a degree = 那麼
Tai Nichi Dai Jiten 臺日大辭典 (A Comprehensive. Taiwanese-Japanese
Dictionary) shows it with entering tone (Yang-Ru).
More is discussed at: http://www.gophor.com/hokkien/viewthread.php?tid=5280&extra=page%3D1
The character 爾 (niq) shows up with Yang-Qu tone in the Taiwanese
Ministry of Education's dictionary (so it would be something like
"nir" in Tadpolenese, or "nirl" if Yang-Shang tone.) However, because
Tai-Nichi Dai-Jiten shows it with Yang-Ru tone, we might as well
follow its practice. In Taiwanese, phonetically it is impossible to
tell apart the three tones (Yang-Shang, Yang-Qu, Yang-Ru in the case
of final glottal stop) when the word never appears in isolation, or
In short, it seems reasonable to use "hiah'niq" for 遐爾.