The "Pima heirloom knotted gown" by Velvet Fawn is a type of dress or gown made by the brand. "Pima" refers to the type of fabric used, which is Pima cotton. Pima cotton is known for its softness, durability, and high quality. "Heirloom" suggests that the gown is made with meticulous craftsmanship and attention to detail, possibly featuring intricate embroidery or delicate embellishments. The term "knotted" could refer to a specific design element, such as a knot or tie detail on the gown. Overall, this description implies a luxurious and elegant gown made from high-quality Pima cotton, with a special design feature.