Origin of the Word Huguenot
Competing suggestions
A From Etymology online (http://www.etymonline.com/h4etym.htm)
Huguenot - 1562, from M.Fr., originally political, not religious. The name was applied in 1520s to Genevan partisans opposed to the Duke of Savoy who joined Geneva to the Swiss Confederation, and is probably an alteration of Swiss Ger. Eidgenoss "confederate," from M.H.G. eitgenoze, from eit "oath" + genoze "comrade." The form of the Fr. word probably alt. by assoc. with Hugues Besançon, leader of the Genevan partisans. In Fr., applied generally to Fr. Protestants because Geneva was a Calvinist center.
B .... many consider it to be a combination of Flemish and German. Protestants who met to study the Bible in secret were called Huis Genooten, meaning "house fellows." They were also referred to as Eid Genossen, or "oath fellows" meaning persons bound by an oath. Two possible but different derivations incorporating this concept can be found in the Encyclopedia Britannica:
1. "Huguenot", according to Frank Puaux, at one time Président of the Société Française de l'Historie du Protestantisme Francais and author of the article about the Huguenots in the eleventh edition of the Encyclopedia Britannica: "is the name given from about the middle of the sixteenth century to the Protestants of France. It was formerly explained as coming from the German Eldgenosen, the designation of the people of Geneva at the time when they were admitted to the Swiss Confederation. This explanation is now abandoned. The words Huguenot, Huguenots, are old French words, common in fourteenth and fifteenth-century charters. As the Protestants called the Catholics papistes, so the Catholics called the protestants huguenots. The Protestants at Tours used to assemble by night near the gate of King Hugo, whom the people regarded as a spirit. A monk, therefore, in a sermon declared that the Lutherans ought to be called Huguenots, as kinsmen of King Hugo, inasmuch as they would only go out at night as he did. This nickname became popular from 1560 onwards, and for a long time the French Protestants were always known by it."
2. The current edition Encyclopedia Britannica offers a somewhat different explanation, although agreeing the word is a derivative of the German word Eldgenosen: "The origin of the name is uncertain, but it appears to have come from the word aignos, derived from the German Eldgenosen (confederates bound together by oath), which used to describe, between 1520 and 1524, the patriots of Geneva hostile to the duke of Savoy. The spelling Huguenot may have been influenced by the personal name Hugues, "Hugh"; a leader of the Geneva movement was one Besancon Hugues (d. 1532)."
C THE DICTIONARY OF PHRASE AND FABLE BY E. COBHAM BREWER (NEW AND ENLARGED EDITION, 1894
Huguenot (U-gue-no). First applied to the Reformed Church party in the Amboise Plot (1560). From the German cidgenosscn (confederates) Huguenot Pope (La pape des Huguenots). Philippe de Mornay, the great supporter of the French Protestants. (1549-1623.)
D Websters Revised Unabridged Dictionary 1913
Huguenot (Hu"gue*not) n. [F., properly a dim. of Hugues. The name is probably derived from the Christian name (Huguenot) of some person conspicuous as a reformer.] (Eccl. Hist.) A French Protestant of the period of the religious wars in France in the 16th century.
E One website claims the term comes from the French word Huguon: one who walks by night or perhaps from the German word Eidgenossen, meaning confederate, or even from the name Hugues, a Genevese Calvinist.