means An underground horizontal stem that sends out roots and shoots from its nodes, letting a plant spread and survive as a connected network rather than a single upright thing.

from From Greek 'rhizoma,' meaning a mass of roots, built on 'rhiza,' root — the same ancient root (so to speak) that gives us 'rhizoid' and lurks inside 'licorice' (Greek 'glykyrrhiza,' literally 'sweet root'). It entered English in the 19th century as a botanical term, and was later borrowed by philosophy to name sprawling, decentralized networks — a fitting afterlife for a word that already meant something spreading underground in every direction.