progress at great speed
gallop - run
To ‘gallop’ means to run very quickly. The word was originally used to describe a horse moving at top speed. While it is still regularly used in that context, the term has also been adapted to express a person doing something quickly, and something, such as a process or situation, that develops rapidly, thus making it difficult to manage or control.
The horse galloped to the finish line, winning the race by a distance. I’m so glad I put my money on that one!
With the deadline looming, we knew we would have to complete the order at a gallop if we were to have any chance of making it.
The galloping spread of the virus made it very difficult to predict or halt in any way. That’s why countries were quickly overwhelmed.