The name appears most frequently as “Tayer,” “Tawier,” or “Tawyer” in the parish registers at Thornbury.  General Bezaleel Thayer, in his 1874 Memorial to the Thayer Name states the following:

The word “Thayer,” as Judge Horace Metcalf’s note to Dr. Elisha Thayer of Dedham, Massachusetts who had examined the England law reports on the subject of the Thayer name spelled in the different ways in those reports: Thayer, Thear, Their, Theyer, etc.  The “There” is of German origin, and in that language signifies an ox or a cow, or dealer in such, as I am told, consequently it seems probably that our ancestors took their sirname [sic] from the continent, and it is synonymous with a bullock in the English language.

From the NEHGS Register of July 1906 we learn the following:

The root of the family name, from “taw”: to dress skins, is made clear in the earlier spelling of the name at Thornbury.  The letter “h” was added soon after the emigrants came to New England, but in the line of the family descended from Ferdinando2 (Thomas1) of Mendon, Mass., that letter was silent –as in Thomas and Thompson– until early in the last century…  The name is now extinct in Thornbury.

An added note comes from my correspondents, Ralph Clinton (“Clint”) Thayer and wife, Constance, who in June of 2000 traveled to Barbados.  States Clint:

“The natives cannot or do not say ‘Thayer,’ it comes out as ‘Tayer.'”

From the NEHGR Vol. 37, p. 84: NOTES AND QUERIES:

–During a recent stay in England I made a visit to the parish of Thornbury, which I understood to be the “old home’ of the Tayers, or Thayers, and there through the kindness of the Rev. Thomas Walters, Viscar, who assisted me in deciphering the early records in the church, and William Osborne Maclaine, Esq., of Kyneton House, who gave me much information on the subject, I obtained the following facts, which may be of interest to those connected with the family.  The Tayers are of Saxon origin, and the name is thought to be derived from the Saxon “taw,” to tan–and hence a “tanner.”  The family is now extinct, but they owned lands in the parish from the reign of Edward II, and were all described with the affix “gent.”  Thomas Tayer, who came to America…. In this country the grandchildren of the first Thomas Tayer spelled the name Thayer, and is has so continued to the present time.     H.E.W.  Boston, Ma