The crossword solution for the term 'Hammer is One' is RAPPER, a six-letter word. Rapper is a term used to describe a musician who performs hip hop music, which is a genre of popular music that originated in the United States in the 1970s. The term 'Hammer is One' is likely referring to the rapper MC Hammer, who was one of the most successful and influential rappers of the late 1980s and early 1990s.