A taproot is a single, thick main root that grows straight down into the soil, like a sturdy underground anchor. If you've ever pulled up a dandelion and noticed one thick root going deep into the ground (often breaking off because it goes so far down), you've seen a taproot. Carrots and radishes are taproots too: they're actually the swollen root itself, storing energy and nutrients for the plant.

Taproots work differently from the spreading, branching roots of grass. While those plants send roots out in many directions like a web, a taproot drives downward, sometimes reaching water and minerals far below the surface. This makes plants with taproots incredibly hardy: they can survive drought better because they can reach deep water that shallow-rooted plants can't access.

In conversation, people sometimes use taproot as a metaphor for something fundamental that goes deep, like calling a person's core values the “taproot” of their character. But usually, the word simply describes that thick, downward-growing root that anchors a plant firmly in place.