English
ineffably
From ineffable + -ly.
A compound of ineffable + -ly
Proto-Indo-European *bʰeh₂- ‘to speak’
…
Latin effor ‘to speak, say out, utter’
Latin effābilis ‘utterable’
Latin ineffābilis ‘unutterable, unpronounceable’
Middle French ineffable
English ineffable
Today it means
adv indescribably; to a very great degree or extent.
Language periods are conventional ranges, not dates for this word.
Etymograph / ineffably