Rung of a ladder is an important part of a ladder, providing the support for the user to climb up and down. It is typically made of metal or wood and is usually round or rectangular in shape. The term 'rung of a ladder' can be broken down into two words: 'STEP' and 'xbar'. STEP is a 4-letter word meaning a single movement of the foot in walking or running. Xbar is also a 4-letter word which refers to a horizontal bar used as a support in construction or engineering. Together, these two words form the term 'rung of a ladder', which is an essential part of any ladder.