Which word refers to a scarcity or lack of something?

The term "dearth" specifically describes a scarcity or lack of something, particularly in the context of food or resources. When there is a dearth, it implies that there is not enough of a particular item available to meet demand or needs. This word encapsulates the idea of insufficiency and highlights a significant gap between availability and necessity.

In contrast, the other terms convey opposite or unrelated concepts. "Surplus" suggests an excessive amount of something, indicating that there is more than enough. "Abundance" refers to a plentiful quantity or a large supply, which again points to a positive availability. Lastly, "excess" implies an overflow or more than what is needed, further distancing it from the notion of scarcity. Thus, "dearth" is the appropriate choice for expressing a lack.