When you look up on videos in eJOY App, the default definition will be shown in English. If you want to see translation in your native language first, you can do this in Settings.
In the video you’re watching, go to Settings.
In the Settings, go to Look up > Show translation first.
NOTE: When you go offline, only translation for single word is available. This means you won’t be able to translate a phrase. If you want offline translation, you can download a suitable dictionaries in App Settings > Offline Data.