A categorized collection of English word lists, created manually
I put these word lists together myself manually. They are NOT exhaustive lists of every possible thing in each category. In each category, I thought of as many words as I could and wrote them down. Then I asked relatives and friends for suggestions of additional words and added these in. In some cases (e.g. colors, trees) I then researched on the internet from a variety of sources; when I found an item that wasn't already on the list I added it in. The list of animals has an additional property: it contains only animals whose plural can be generated by simply adding 's' to the singular versions given in the list.
These word lists can be used without attribution: I have put this repository in the public domain under the Unlicense.