The crossword solution for the term 'Smoothie Seed' is CHIA, which is a four-letter word. CHIA seeds are a type of edible seed that come from the Salvia hispanica plant, native to Central and South America. They are a popular ingredient in smoothies due to their high nutrient content, including omega-3 fatty acids, antioxidants, and fiber. CHIA seeds can also be eaten raw, added to yogurt or oatmeal, or used as a topping for salads.