脊

Originally a pictograph.

Bronze script (金文):

Represents the spinal ridge of a fish or animal, long and segmented.

Clerical / Seal script (篆書):

The bottom component 肉 (“flesh”) was added → making it a semantic + pictorial compound, indicating a body part.

Thus the meaning “spine / backbone” is ancient and literal.

《說文解字》 (Shuowen Jiezi):

「脊，背也。」

“脊 means the back.”

척추 (脊椎) — spine, vertebral column

흉추 (胸椎) / 요추(腰椎) — thoracic / lumbar vertebrae (脊 used conceptually)

척수 (脊髓) — spinal cord

등마루 (脊) — literary use for “back ridge”

脊 belongs to the group of anatomical “flesh + structure” characters:

髓 — marrow

椎 — vertebra

腔 — cavity

肋 — rib

In East Asian literature often describes anything with a narrow raised crest (mountains, roofs, waves).

Classical citations:

《淮南子・本經訓》 (Huainanzi)

「虎脊如戟。」

“The tiger’s spine is like a halberd blade” — emphasizes sharp, raised ridge.

《後漢書・馬融傳》 (Book of the Later Han Dynasty)

「脊骨皆折。」

“All the bones of the spine were broken” — anatomical usage.

Not to be confused with 背:

背 — the back (surface)

脊 — the spine / ridge (central structure)