Having second thoughts is a phrase used to describe the feeling of regret or uncertainty about a decision that has already been made. The crossword solutions for this phrase are HESITATE (8 letters), SORRY (5 letters), and RUING (5 letters). HESITATE means to pause or be uncertain before taking action, SORRY is an expression of regret or sorrow, and RUING is to feel deep regret or remorse. Together, these words can be used to describe the feeling of having second thoughts.