1. a large dome-shaped or domed structure, especially a sports stadium or arena with a retractable or fixed roof
Usage: often capitalized when referring to the specific Houston Astrodome; can be used generically for any large domed sports facility
2. a transparent dome or window on an aircraft, typically used for observation or navigation
Usage: aviation/aerospace term; less common in everyday usage

Examples

• The Astrodome in Houston was one of the first air-conditioned sports stadiums in the world.
• The team played their home games in the astrodome during the winter months.
• Modern astrodomes feature retractable roofs that can open on clear days.
• The aircraft's astrodome provided pilots with excellent visibility of the sky.
• Many cities have built new astrodomes to host concerts, sports events, and conventions.