The crossword solution for the term 'Prominent Rock on a Hill' is TOR, which stands for a rocky hill or outcrop. TOR is a Celtic word meaning 'rocky hill' and is commonly used in the United Kingdom to refer to a prominent rock formation on a hill. TOR formations are typically found in areas of high elevation, such as the moorlands of Devon and Cornwall. They are often associated with ancient sites, such as Iron Age hill forts, and are popular tourist attractions.