https://www.learnthat.org/word_lists/view/3068
Here is one list I found online.
https://www.learnthat.org/word_lists/view/3068
Here is another one I found.
What about just pulling words from subject areas? Preteaching words before math, science, social studies and reading lessons really increases understanding. The words would be pretty easy to pull from standards, textbooks and other teaching resources.
This is a great resource for learning math related vocabulary.
http://amathsdictionaryforkids.com/
http://www.readwritethink.org/classr...les-30068.html
This is a great place to create your own crossword with vocabulary words.
Good luck!