He made an unspellable animal sound and rushed at the blackness.
"Breaking Point" by James E. Gunn
It was soon again filled with such glorious visions as drove out all dark shadows of unspellable words and unsolvable problems.
"'Lizbeth of the Dale" by Marian Keith
Seeing who came, she uttered one of anger's unspellable words, a snort.
"A Yankee from the West" by Opie Read
An unpronounceable, unspellable, unmanageable name.
"The Nerve of Foley" by Frank H. Spearman