Yee-haw is a phrase used to express joy or excitement, especially in the American South. It is often used as a cheer or a rallying cry. The crossword solution for this term is 'Oater Cry, ' which is a reference to the Western films of the early 20th century, also known as 'oaters.' These films often featured cowboys and other characters shouting 'yee-haw' as they rode horses and engaged in exciting activities.