1. A formal investigation to determine the facts of a legal case: The police are conducting an official inquiry into what caused the construction crane to fall and crash through the roof of a grocery store killing a woman and injuring several other customers and workers.
2. An effort to obtain information: Alfred was told that he was not allowed to make inquiries about the salaries of his fellow workers.

Sam's Aunt Susan made an inquiry about whether there would be any available tickets for the symphony the next night.

3. A close examination of something because of a search for information or truth: Dr. Celia Smith held an inquiry with her interns about the procedure that should be followed for Gwen who had been admitted to the hospital for an emergency operation.