unutterabilityn.
Etymology: Previous versions of the OED give the stress as: unutteraˈbility.
the mind > mental capacity > intelligibility > unintelligibility > inexpressibility > [noun] > instance of
1837 T. Carlyle II. i. iii. 29 They come; with hot unutterabilities in their heart.
This entry has not yet been fully updated (first published 1926; most recently modified version published online June 2019).