great guns adv. phr.,
informal 1. Very fast or very hard.
■ Usually used in the phrases "blow great guns", "go great guns".
The wind was blowing great guns, and big waves beat the shore. The men were going great guns to finish the job. Compare: FAST AND FURIOUS.
2. Very well; successfully.
Smith's new store opened last week and it's going great guns. [TahlilGaran] English Idioms Dictionary ▲