1. extremely slow; moving or happening at a very slow rate
Usage: technical; scientific

Examples

• The ultraslow motion camera captured every detail of the water droplet falling.
• Scientists used ultraslow cooling techniques to study the material’s properties.
• The ultraslow earthquake lasted for several minutes instead of seconds.
• Researchers observed ultraslow waves in the ocean depths.
• The ultraslow chemical reaction took weeks to complete.
• Ultraslow internet speeds made downloading files nearly impossible.