[batrat]

Don't know the technical terms but how is "unresponsive to input" when you can interact with the lock screen. For example swiping/expanding notifications, change songs, etc. For me "unresponsive to input" to a state of "responsive to input" would be the power/home button let's you interact with the screen.

[unfamiliar]

Fine. Change "unresponsive to input" to "unresponsive to all but a very restricted subset of all possible inputs".