Double quick is a military term that refers to a fast pace of marching or running. This term has its synonyms that can be used interchangeably. Some of the synonyms for double quicks are "hurriedly," "swift," "expeditious," "brisk," "accelerated," "fleet," "rapid," "quick," and "speedy." These words convey a sense of urgency and haste, which is crucial in the military and other contexts where speed is of the essence. Whenever you need to describe a fast pace, you can use any of these synonyms instead of double quicks to add variety to your writing or speech.