COMMON If someone floats a trial balloon they suggest an idea or plan in order to see what people think about it. The administration has not officially released any details of the president's economic plan, although numerous trial balloons have been floated. Note: Other verbs can be used instead of float. Weeks ago, the Tories were flying a trial balloon about banning teacher strikes. Note: You can call an idea or suggestion that is made to test public opinion a trial balloon. The idea is nothing more than a trial balloon at this point. Note: Balloons were formerly used to find out about weather conditions.