The term PLANT PROP can be broken down into two crossword solutions: STEM, which is a four-letter word, and PROP, which is a three-letter word. The word STEM refers to the main stalk of a plant, which supports the leaves, flowers, and fruits. The word PROP refers to something that supports or holds up a plant, such as a stake, trellis, or cage. Together, these two words describe the support system for a plant, which is essential for its growth and development.