The term 'voluminous hairstyle' can be summarized by the crossword solution of 'AFRO'. An AFRO is a hairstyle that is characterized by a large, rounded shape and is often associated with people of African descent. It is created by allowing the natural hair to grow out without any chemical or heat treatments. The hairstyle is known for its fullness and volume, making it a popular choice for those looking to make a statement.