From The Rhyme of the Southern Rivers: With Notes Historical, Traditional, Geographical, Etymological, etc. by Martin V. Moore, published in 1897.

NOTES ON THE RIVERS OF VIRGINIA

2. SHENANDOAH. This is really the Shannon-Doah, or Shannon-Toah, the final term “Toah” a well-known Indian word for river. The word has three forms in different dialects: It is found as “Taquah,” as “Toah,” and more briefly as “Tau.” The writing as “Ta-ho” is precisely the same original word. It shows origin in the germ-words “Te” and “owa,” or “au,” water, its literal significance that of deep water. All the different forms are found in the names of deep waters in various parts of the world. As Ta-ho, it is the native name of a deep lake in California. In Spain there is a deep river having the prehistoric title Ta-ho, the word appearing in the modern Spanish idiom as Tagus. In China the writing in English letters is Tai. The oldest form of the word is in the Hebrew in the writing Toah, in the name of a water, Neph-Toah. A term for water simply is found in many languages in the English writings “Owa,” “Oah,” “Owee,” “Au-wa,” and “A-haw.” The old Teutonic form of the word is “A-wa,” or in the Roman idiom “A-qua.” This, in a composite with the root-word for the deep “Te,” gives the form of the term as “Taqua” seen in the native names of many of the deep waters of America. Other forms of this word will be referred to in Note 61. The term “Shannon” in the Virginia name appears to be of more modern origin. It corresponds to the old Irish word Shannon, the name of a river in Ireland.

In loving memory of Dr. Jean Allen Battle.