# violent waves in the sea

As the sea's waves are blown by a strong wind, so the ungodly people are easily moved in many directions. (See: [[rc://en/ta/man/translate/figs-metaphor]])

# foaming out their own shame

As wind causes wild waves to stir up dirty foam—so these men, through their false teaching and actions, shame themselves. Alternate translation: "and just as waves bring up foam and dirt, these men pollute others with their shame" (See: [[rc://en/ta/man/translate/figs-metaphor]])

# They are wandering stars

Those who studied the stars in ancient times noticed that what we call planets do not move the way that stars do. Alternate translation: "They are like moving stars" (See: [[rc://en/ta/man/translate/figs-metaphor]])

# for whom the gloom of thick darkness has been reserved forever

Here "darkness" is a metonym that represents the place of the dead or hell. Here "the gloom of thick darkness" is an idiom that means "a very dark place." The phrase "has been reserved" can be stated in active form. Alternate translation: "and God will put them in the gloom and darkness of hell forever" (See: [[rc://en/ta/man/translate/figs-metonymy]] and [[rc://en/ta/man/translate/figs-idiom]] and [[rc://en/ta/man/translate/figs-activepassive]])