Developers like MobiSystems offer official "Concise Oxford" apps on the Google Play Store and Apple App Store. These often include a free version with ads or a limited trial period for the full "Premium" features.
The is a staple of the English-speaking world, offering a perfect balance between the massive multi-volume Oxford English Dictionary and smaller, desk-sized versions. Concise Oxford English Dictionary 13th Edition Free Download
For historical research, older, out-of-copyright versions of the Concise Oxford Dictionary are available for free viewing and borrowing through the Internet Archive . Why Choose the Concise Oxford? Most libraries provide members with free remote access
This is the most reliable method. Most libraries provide members with free remote access to Oxford’s digital reference suite. You can often sign in with your library card on the official OED or Oxford Dictionaries websites. For historical research