" Here, "waxing" and "waning" are opposites, where "waxing" is increasing, and "waning" is decreasing. " (taking it very seriously - making "heavy" pronouncements about it) "To wax eloquent" is a very common phrase, which means to become increasingly more eloquent. When the moon is progressing in its phases from "new" toward "full," we say that it's waxing.
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