Readers of The Figures of Earth: A Comedy of Appearances, have probably wondered, as I have for nearly four decades, about the lore surrounding the word “geas,” apparently meaning a binding pledge or promise, which appears in the book repeatedly.
The word suggests the chivalrous approach to life that James Branch Cabell contrasts with the poetic and gallant attitudes.
The word popped into my head again today, and upon this occasion of memory I looked it up using Google’s ngram viewer.
The most interesting use I found, preceding Cabell, is by William Sharp writing as Fiona Macleod in 1899. The book is The Dominion of Dreams, and the word can be found in the chapter titled “Honey of the Wild Bees.”
“Geas,” we discover, is singular; “geasan” is the plural. (In The Grimoire, from 1990, we are told the plural is “geasa.”)
Look for the volume on Google Books. The Dominion of Dreams actually appears more than relevant to Cabell’s work — the title indicates that clearly enough — even disregarding this particular strange word’s meaning and etymology, there illumined.
twv
Wirkman Comment 
Sharp seems to have lost count.
[1] Bobarân asked the stranger about the berries and about what he had done with them. (This is baldly asserted in the first paragraph, though Bobarân’s exact words are not offered.
[2] Bobarân asked the stranger if he were of Emhain Abhlach.
[3] Bobarân then asked the stranger if his name and that of the stranger’s father were known to Bobarân.