NAILS' The term 'NAILS A TEST' can be broken down into two crossword solutions, 'ACES' and 'NAILS'. The term 'ACES' is a four letter word that means to do something perfectly or to get the highest score possible. The term 'NAILS' is a four letter word that means to hit or drive something in with a hammer or other tool. Together, the phrase 'NAILS A TEST' implies that one has achieved the highest score possible on a test.