waiting..
    

    

    person with backpack waiting for the train
    

    to remain stationary in readiness or expectation
    

    


    person waiting for train with their feet crossed
    

    to stay in place in expectation of
    

    


    person waiting with industrial structures in the distance
    

    to pause for another to catch up
    

    


    train coming to a stop at platform
    

    to be ready and available
    

    


    person waiting in the lobby
    

    essential

    es·​sen·​tial | \ i-ˈsen(t)-shəl

    something necessary, indispensable, or unavoidable