english
1
general::
Phrase(s): trial balloon a test of someone’s or the public’s reaction. • It was just a trial balloon, and it didn’t work. • The trial balloon was a great success.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
An idea or plan advanced tentatively to test public reaction, as in Let's send up a trial balloon for this new program before we commit ourselves. This expression alludes to sending up balloons to test weather conditions. [c. 1930]
American Heritage Idioms