From the second edition (1989):
bigot, n. and a.
(ˈbɪgət) [a. F. bigot, of unknown origin: see below.]

A. n.

1. a. A hypocritical professor of religion, a hypocrite. b. A superstitious adherent of religion.

1598 Speght Chaucer, Bigin, bigot, superstitious hypocrite [1602 adds or hypocriticall woman]. 1653 Urquhart Rabelais i. xl, He is no bigot or hypocrite. 1656 Blount Glossogr., Bigot (Fr.), an hypocrite, or one that seems much more holy then he is, also a scrupulous or Superstitious fellow. 1664 H. More Myst. Iniq. 436 One part of their Church becomes Sotts and Bigots.

2. A person obstinately and unreasonably wedded to a particular religious creed, opinion, or ritual.

1661 Cowley Cromwell Wks. II. 655 He was rather a well-meaning and deluding Bigot, than a crafty and malicious Impostor. 1741 Watts Improv. Mind i. Wks. (1813) 14 A dogmatist in religion is not a long way off from a bigot. 1844 Stanley Arnold II. viii. 13 [Dr. Arnold] was almost equally condemned, in London as a bigot, and in Oxford as a latitudinarian.

b. transf. (Of other than religious opinions.)

1687 Congreve Old Bach. i. v, Yet is adored by that bigot Sir Joseph Wittol as the image of valour. 1838 Hallam Hist. Lit. i. vii. §14 I. 395 Lord Bacon, certainly no bigot to Aristotle. 1863 Kingsley Water-Bab. vi. 290 The children of Prometheus are‥the bigots, and the bores.

3. Comb., as bigot-maker.

a1720 Sheffield (Dk. Buckhm.) Wks. (1753) II. 155 The best of all the Bigot-makers that ever I read of.

B. adj. [Often merely attrib. use of n.]

1623 Ld. Herbert in Ellis Orig. Lett. i. 298 III. 164 The most common censure, even of the bigot party. 1680 Dryden Kind Kpr. Ep. Ded., In a Country more Bigot than ours. 1751 Smollett Per. Pic. lxii, The crazed Tory, the bigot Whig. 1844 Kinglake Eothen xxvii. (1878) 345 Old bigot zeal against Christians.

[In OF. Bigot appears first in the romance of Girart de Roussillon (12th c.) as the proper name of some people, apparently of the south of Gaul. Hence already in the 17th c. it was suggested by Caseneuve, that it might be an OF. form of Wisigothus, Visigoth; the relations between the Visigoths of Toulouse who were Arians, and the Franks who were Catholics, being such as readily to attach to the name of the former the connotation of ‘detestable foreigner’ or ‘foreign heretic.’ But modern Romanic scholars find phonetic difficulties, besides that there is no evidence that the name Wisigothi was preserved in the vulgar tongue. Slender support to some connexion with the Goths is suggested by the med.L. form Bigothi (Du Cange). Whether the Sp. bigote, moustache, is in any way connected, cannot be decided. According to Wace bigoz, bigos was applied opprobriously by the French to the Normans, which shows that the word had then acquired some connotative force; the legend that it originated in the refusal of Hrolf or Rollo to kiss the foot of Charles the Simple, when, in the words of the 12th c. chronicler, ‘lingua Anglica (!!!) respondit Ne se, bi got, quod interpretatur Ne per Deum’ (No by God!), is absurdly incongruous with facts. The opprobrious sense in Wace was certainly not that of ‘superstitious’ or ‘hypocrite,’ as in later F. and Eng.; materials to show how the latter was developed are wanting, but there is evidence to show that the feminine bigote was subsequently applied in opprobrium to the Beguines (see Beguta, Bigutta, in Du Cange): our first quotation identifies bigot with bigin or beguine. In early times the word became a Norman family name as in Roger Bigod earl of Norfolk.]