The term 'Hit Dead-Center' can be summarized by two crossword solutions: 'Nailed' (6 letters) and 'NAIL' (4 letters). 'Nailed' is an informal phrase that means to have achieved something with great accuracy or success. It is often used in the context of hitting a target or goal. 'NAIL' is a verb meaning to fasten or secure something with a NAIL or similar object. In this context, it could mean to hit a target or goal with great accuracy or success.