Final answer:
The terms wax and wane are antonyms as they have opposite meanings, commonly used to describe the growing and diminishing phases of the moon.
Step-by-step explanation:
The relationship between the terms wax and wane is that they are antonyms. The term 'wax' means to increase or grow, commonly used in reference to the moon's phases as it appears to grow fuller. Conversely, 'wane' means to decrease or diminish, again often referring to the moon as it appears to shrink to a new moon. These two words have opposite meanings, making them antonyms of each other.