tap-root

noun Botany.

1. a main root descending downward from the radicle and giving off small lateral roots.

noun

1. the large single root of plants such as the dandelion, which grows vertically downwards and bears smaller lateral roots

n.c.1600, from tap (n.) + root (n.).

1. The main root in gymnosperms, eudicotyledons, and magnoliids, usually stouter than the lateral roots and growing straight downward from the stem. The taproot develops from the primary root. The taproot and its lateral roots penetrate deeper into the soil than the fibrous roots characteristic of monocotyledons. Compare fibrous root.

The single deep root of many deciduous trees that forms the basis for their root systems.