caput

Caput is Latin for head. A promontory — a piece of land jutting into the sea — is the head of the land, the furthest point. Italian took caput and made it capo, which in its geographic sense means a headland. Spanish made it cabo. Portuguese made it cabo as well — Cabo da Roca, Cabo Verde, Cabo de Boa Esperanca. English borrowed the geographic term through Old French cap, which became 'cape.'

The garment called a cape has the same origin. A capa in Late Latin was a head-covering, from caput. The cloak that covered the head extended to cover the shoulders and eventually the whole body. The head-covering became a shoulder-covering became a full-length outer garment. The chapel — capella — also comes from this root: the cloak of St. Martin of Tours was kept as a relic, and the building that housed it was called a capella, a little cape.

The great capes of navigation are all headlands: the Cape of Good Hope, which Bartholomeu Dias rounded in 1488; Cape Horn, which the Dutchman Willem Schouten rounded in 1616; Cape Cod, which the Pilgrims named in 1602 for the fish they found there. Each is a point where land pushes its head into the ocean. Sailors feared them because the weather at capes is violent — currents collide, winds accelerate, waves build.

The word has split so thoroughly that most English speakers do not connect the geographic cape with the garment cape, let alone with 'captain' or 'chapter' or 'capital' — all from the same caput. The head is everywhere. It is in the cape of land, the cape of cloth, the captain of the ship, and the capital of the country. Latin's word for head runs through English like a river.