What does “columna vertebral” mean figuratively in Spanish?

Literally, la columna vertebral is your “spinal column” — the anatomy term for your backbone. But Spanish uses it just like English uses “backbone”: for the central thing that holds a whole system up. In the clip, Cuenca’s tram becomes la columna vertebral de una movilidad nueva — “the backbone of a new kind of transit.” The pattern la columna vertebral de X = “the backbone of X” works cleanly in speech and writing.

It’s a neutral, register-flexible metaphor you’ll meet everywhere: el petróleo es la columna vertebral de la economía, esta ley es la columna vertebral del sistema. Note the gender and agreement — it’s feminine (la columna), and vertebral stays the same for masculine or feminine nouns. Reach for columna vertebral whenever you’d say “the backbone” or “the central pillar” of something.