burgeon

This word carries a strong sense of organic, healthy expansion. It evokes the image of a bud opening into a flower, suggesting that the growth is not just fast, but natural and full of potential. It is typically used in formal or literary contexts to describe things like economies, populations, or artistic movements. While "grow" is neutral, "burgeon" implies a sudden surge of vitality and success. It is rarely used for negative growth, such as the spread of a disease, which would instead be described as "proliferating" or "spreading."