The Penguin Dictionary of Curious and Interesting Geometry -- David Wells
The Penguin Dictionary of Curious and Interesting Numbers -- David Wells
Longman Mathematics Handbook -- Keith Selkirk
Penguin Dictionary of Mathematics -- David Nelson (Ed.)
The Oxford English Dictionary -- John Simpson (Chief Ed.)
Each of these is warmly recommended as a source for further information about many of the words at thesaurus.maths.org. Any errors or omissions are entirely my own responsibility.
Any apparent plagiarism is never intentional, and I would be happy to rephrase anything that is felt to be too close to a given text.
Lyndon Baker
Rupert Levene
Emma McCaughan
Benjamin Wardhaugh