襦袢

A foreign shirt slipped under the kimono and stayed there for centuries. Japanese juban, written 襦袢, names the under-robe worn beneath outer kimono, and the word is generally traced to sixteenth-century contact with Portuguese merchants and missionaries. The likely source is Portuguese gibão, a fitted doublet or jerkin, heard in Japanese ports such as Nagasaki after 1543. Japan borrowed the garment term and then made it unmistakably Japanese.

The phonology tells the story of adaptation. A Portuguese form with a palatal onset and nasal ending was reshaped to Japanese syllable structure as juban or jiban-type variants before stabilizing. The clothing changed too. What arrived as an Iberian upper garment became, in Japanese use, an inner robe fitted to layered dress.

By the Edo period, juban was fully naturalized and had spawned compounds such as nagajuban, the long under-kimono. At that point the foreignness of the word had gone quiet. This is how strong borrowings behave: they stop performing their passport. They simply become necessary.

Today juban remains part of kimono vocabulary, whether in formal wear, tea practice, theater, or the wedding industry. The word preserves an early-modern encounter between Japan and Europe, but it does so discreetly. Most borrowed words brag about travel. This one went underneath.