Trial balloons are a form of testing public opinion on an idea or policy before it is officially implemented. They involve releasing information to the public in order to gauge reactions and feedback. The two crossword solutions for the term 'trial balloons' are 'tests' (5 letters) and 'FEELERS' (7 letters). Tests refer to the process of gathering data and feedback from the public, while FEELERS refer to the act of gauging public opinion.