A pea is a plant that grows small, green, edible seeds — also called peas. When you think of peas, you undoubtedly picture the little green things on your plate beside the mashed potatoes.
You might think of peas as vegetables — more specifically, they are legumes. They are actually the seeds, or fruit, of a plant that most commonly climbs like a vine and produces long pods that contain peas. The word started as pease in Middle English, which referred to both the singular and the plural (like wheat and corn). The Greek root is pison.