Primitive Christianity Revived, Again
I still refer to what I "do" in meeting as "waiting upon the Lord" even though I am not Christian.
If we consider a Quaker meeting as opening up three lines of communication, listening for what others might have to say, listening for what that of God within us might have to say, and giving others the opportunity to hear what we might say. Of course it is hard to draw boundaries between these lines of communication, but none of them happen so readily without the silence.
I see the silence of meeting as a vehicle that enables these things to happen. Without the silence these things can still take place, but the silence is preparing the way; making important communication more obvious and open to greater sharing . It's like laying a tablecloth before a meal, it somehow changes the everyday table into something different and, of course allowing food to be laid upon it. Silence prepares the members of the meeting, for something meaningful and important to happen.
Is it waiting? To my mind no more than the tablecloth is waiting for the food.