Propel a tandem is an activity that requires two people to work together. It involves one person pedaling the tandem bicycle while the other steers and provides balance. The term 'propel a tandem' is derived from the word 'PEDAL, ' which is a five-letter word used to describe the act of pushing down on the pedals of a bicycle in order to move it forward. This activity is often enjoyed by couples or friends who want to explore the outdoors together.