The term 'ladder rung' refers to the horizontal bars of a ladder that are used to climb up and down. The crossword solutions for this term are 'STEP' (4 letters), 'SPOKE' (5 letters), and 'STAVE' (5 letters). A STEP is the single bar of a ladder, while a SPOKE is a round bar that is connected to the steps and provides additional support. A STAVE is a thin, flat bar that is also connected to the steps and provides additional stability. All three components are necessary for a ladder to be safe and functional.