Slang References

The best reference book on slang I've found is Cassell's Dictionary of Slang. It has more than 85,000 entries and over 1,500 pages. What's particularly useful is that most entries indicate when and where the word was used. For instance, here are the entries under mope:

What's harder is doing the reverse, i.e., finding a slang term for a particular meaning you have in mind. For normal vocabulary, there is of course Roget's Thesaurus. And guess what? There's also a slang version, The American Thesaurus of Slang. I believe this was compiled in the 1930s and '40s. There are a lot of editions around, used, and the prices seem to vary a lot. This is just as advertised, but it is specific to the period when it was compiled. That's a little later than my period of research, so I usually check elsewhere before using something from this.

At Google Books, you can find a number of old sources available online, and searchable. For instance, The American Slang Dictionary by James Maitland. This was published in 1891. It's 300 pages long, with perhaps 6,000 entries. 

The journal Dialect Notes had many pieces on terms used in specific regions and by various occupations. Most of these seem to have been assembled by amateurs, but there was a wonderful study of college slang done in 1900 by Eugene Howard Babbitt. He polled faculty members at various colleges to assemble lists and then compiled a comprehensive index.

It's difficult to determine how often a particular word was used in speech, but I do various searches. You can search Google Books for particular dates, and also the newspaper archives at Google and at the Library of Congress. The Brooklyn Public Library has made The Brooklyn Daily Eagle available online, and I imagine there are other newspapers online elsewhere.

In an earlier post, I discussed how the people of the period seemed attracted to slang, but usually toward exaggerated depictions of folksy language.