Definition of modeless in English:

modeless

Pronunciation /ˈməʊdləs/

adjective

  • 1rare In mystical use: not manifested in a particular form; formless.

  • 2Computing
    Designating a program, system, or user interface that allows the user to perform various different types of action without having to switch between different modes of operation; specifically designating a dialog box that does not need to be responded to before the system will permit any other interaction.

Origin

Late 16th century (in an earlier sense). From mode + -less.