- The time at which a planned operation, typically a military one, is set to begin.More example sentences
the appointed time, the critical moment, the moment of truth, the point/moment of decision, the Rubicon, the crux• informal the crunch
- Accompanied by your other three team members, you begin at zero hour of the Clone Wars.
- A few minor adjustments were made to the presentation plan, and we set 3 o'clock as zero hour.
- As zero hour approached, Spanish-language radio stations broadcast appeals for all able-bodied Cuban-Americans to help.