The term 'Restin' Piece' is a crossword solution that consists of four letters: TAPS. TAPS is an acronym for the bugle call 'Taps, ' which is a musical piece played at military funerals and other ceremonies to honor those who have died in service of their country. The song is also known as the 'Last Post' or the 'Day is Done.' It is a somber reminder of the ultimate sacrifice made by those who have served in the military.