The term 'flow copiously' can be summarized by two crossword solutions: GUSH (4 letters) and TEEM (4 letters). Both words refer to a large amount of liquid or other material being released in a continuous stream. GUSH is used to describe a sudden, forceful release of liquid, while TEEM is used to describe a steady, abundant flow. Both words are often used to describe natural phenomena such as waterfalls, rivers, and rain.