Wipe the slate clean is a phrase that means to start anew, to ERASE any mistakes or wrongdoings and begin again. The crossword solutions for this phrase are ERASE and RESTART, both of which are indicative of the idea of wiping the slate clean. ERASE implies removing something that has been written or drawn, while restart implies beginning again from the beginning. Together, these two words capture the essence of the phrase 'wipe the slate clean'.