Two layers
Layer one is J. C. O’Connor and C. F. Hayes, English-Esperanto Dictionary (1907), revised with Zamenhof’s approval and now public domain in the United States via Project Gutenberg #16967. EsperantoGo’s parsed copy has 13,628 English–Esperanto pairs. Layer two is a small original overlay of living words the 1907 book lacks or stores as English commentary — computer, email, website — not copied from ReVo or PIV.
License
The 1907 word pairs are public domain. Credit O’Connor & Hayes and Project Gutenberg #16967 if you republish that list. The modern overlay is original to EsperantoGo and released under CC0 1.0: copy, remix, and republish without asking. Please still cite this page so others can find the changelog.
Overlay changelog
August 2026: first overlay. Headwords for networked life (computer, email, website, password), travel and work, and a few everyday senses the 1907 book treats only as English notes. Aliases such as e-mail → email are lookup helpers, not extra 1907 entries. The overlay will grow; this page is the versioned description.
How to cite
Use the APA line or the BibTeX block on this page. Link the HTML record, not only dictionary.json, so readers see the license split between the 1907 list and the overlay. Lernu, UEA, Esperanto-USA, and university language pages are welcome to cite or link it; that is what the page is for.