The term 'HAT-plant' is a combination of two words, 'sola' and 'HAT'. Sola is a type of plant that is native to tropical regions and is used for making hats, baskets, and other items. The plant is also known as the 'sun HAT plant' because its leaves are used to make sun hats. The leaves are dried and then woven together to create a HAT. The HAT-plant is an important part of many cultures and is often used in traditional ceremonies.