unutterable

adj

1. Not utterable; incapable of being physically spoken or voiced; unpronounceable.
2. Incapable of being articulated or expressed; indescribable, inexpressible.

   “unutterable anguish”

   “[H]e is Sir / The moſt vnutterable covvard, that ere nature / Bleſt vvith hard ſhoulders, vvhich vvere only giuen him, / To the ruine of baſtinados.”

   “Prevenient Grace deſcending had remov'd / The ſtonie from thir hearts, and made new fleſh / Regenerat grow inſtead, that ſighs now breath'd / Unutterable, which the Spirit of prayer / Inſpir'd, and wing'd for Heav'n with ſpeedier flight / Then loudeſt Oratorie: […]”

   “VVhat is to ſpeak? or vvherefore ſhould I ſpeak? / VVhat means theſe Tears, but Grief unutterable?”

   “Still in harmonious intercourſe they liv'd / The rural day, and talk'd the flovving heart, / Or ſigh'd and look'd unutterable things.”

3. Not allowed to be spoken; taboo, unspeakable.

   “Hovv oft the humble Scholar came, / And to your Songs he rais'd his Ears / To learn the Unutterable Name, / To view the Eternal Baſe that bears / The Nevv Creations Frame.”

4. (figuratively)Extremely bad or objectionable; unspeakable.

   “These unutterable people upon the telephone have already ruined my morning's work, so that a little more can hardly matter.”

noun

1. Something which is unutterable (incapable of being physically spoken, incapable of being articulated or expressed, etc.).