If one thing is ~ to another, it is less important than the other thing or is not a major part of it.
The playing of music proved to be ~ to the main business of the evening...
ADJ: oft ADJ to n
If one thing is ~ to another, it is less important than the other thing or is not a major part of it.
The playing of music proved to be ~ to the main business of the evening...
ADJ: oft ADJ to n
Collins COBUILD. Толковый словарь английского языка для изучающих язык Коллинз COBUILD (международная база данных языков Бирмингемского университета) . 2012