Waxed, in a way

GREW

Think of how plants or hair change over time, especially when they become longer or larger in size.

The clue plays on the double meaning of "waxed." While it usually means to apply wax, it can also describe the moon appearing larger as it moves toward a full moon—essentially "growing." The answer "GREW" fits because it sounds like "grew" (past tense of grow), matching the idea of the moon increasing in visibility. It’s a clever twist on how the moon "waxes" by seeming to expand.