green-card

The term "green card" is a classic example of a compound noun formed through metonymy, where an object's physical attribute comes to represent its official function. The literal morphemes are straightforward: "green" describes the color, and "card" describes the physical form. The document was officially known as the "Alien Registration Receipt Card" but was popularly nicknamed for the dominant green color of its earliest versions issued in the post-World War II era. Over time, this colloquial name became the universally recognized term for U.S. permanent residency, persisting even as the card's design and color have changed, demonstrating how a simple descriptive label can solidify into formal legal and cultural terminology.

Structure: green (color) + card (document) - green: From Old English 'grēne', of Germanic origin; related to 'grow'. In this compound, it functions as an attributive adjective describing the card's color. - card: From Old French 'carte', from Latin 'charta', from Greek 'khartēs' (papyrus leaf, paper). In this compound, it functions as a noun meaning a piece of stiff paper or document.