Oxford University Press / Oxford Reference Online.
Available online. (W&L subscription)
Second edition (2008) by Timothy Darvill contains 4,000 entries covering "the essential vocabulary for everyday archaeological work in the English language," including principles, theories, techniques, artefacts, materials, people, places, monuments, equipment, and descriptive terms. Focuses on Europe, the Old World, and the Americas.
A link will be maintained on this library Web page.