An excellent thread.

I just went to my old family Merriam Webster 2nd ed. dictionary c1954. It had two meanings:
1) based on Old French, a hypocrite, esp. a superstitious one.
2) One who is obstinitelly, irrationally, intolerantly attached to one's church, party, belief, opinon.

I have never heard or used bigot in the sense of 1) a hypocrite. I have seen and heard it used as the noun of the word 'prejudice'. To me a bigot is one who is prejudiced, and growing up in Northeast USA I mainly heard it applied against local people who did not want their children bussed to schools so as to increase racial integration.

There is one more meaning, purely personal.

When I was 13 and came into social studies class one day, there were two anomalies. The first was that there was substitute teacher that day. I dont know about other countries, but in the American schools I've gone to, a substitute teacher is treated as entertainment by the children. We made up stories, changed our names, and claimed that we had no homework due, pretty much anything that would get us out of doing work and make the substitute teacher's life more horrible. (I have been a substitute teacher, so "I've looked at life from both sides now"). Anyhow, the other anomaly was that whoever had sat at my desk in the classroom before me had torn sheets of paper into little itty bitty bits no larger than 2 x 2 mm. They had been profoundly bored or had a need to destroy some profoundly moving bit of student literature. I remember being impressed that such a source of entropy had yet to be utilized (Of course, at that age I had no idea what entropy meant). The kid in front of me, Michael Breen, who had the size and bravado of Jimmy Cagney, saw me staring at this pile of bits and immediately called them 'bigots'. And of course, with his help, by the end of the class, all those neatly piled bigots were pretty much evenly distributed around the desks, clothing, and any other available surfaces. As usual, the substitute teacher was not able to pound any sense into our bony little heads and we were roundly cussed out by our proper teacher the next day.

So I feel like adding to my dictionary:

bigot:
3) Minute homogenous samples, bits, or particles of innocuous paper, dust, or 'stuff'.