trial balloon

WordReference Random House Learner's Dictionary of American English © 2025

ˈtri•al balˈloon, n. [countable]

1. an announcement about an action or policy, in order to see what the reaction would be or to gauge out how successful the action would be:
   The president's spokesperson floated the trial balloon of raising taxes.

WordReference Random House Unabridged Dictionary of American English © 2025

tri′al balloon′, 

1. a statement, program, or the like issued publicly as a means of determining reactions in advance:
   The speech was a trial balloon for a new law.

• 1930–35