The term 'Bench-Press Unit' refers to a type of exercise equipment used to strengthen the muscles of the chest, shoulders, and triceps. The exercise is performed by lying on a bench and pushing a weight up and down. The three solutions for this term are REP (3 letters), REPS (4 letters), and DELTS (5 letters). REP stands for repetition, which is the number of times the exercise is performed. REPS stands for repetitions, which is the plural form of repetition. DELTS stands for deltoids, which are the muscles in the shoulder area that are targeted during the exercise.