noun
bun filled with sweet green pea paste
A sweet bread roll filled with うぐいす餡, a smooth paste made from green peas. A traditional Japanese bakery item.
See also: うぐいす餡
朝ごはんにうぐいすパンを食べた。
I had an uguisu-pan for breakfast.
Compound of うぐいす (uguisu, 'Japanese bush warbler') and パン (pan, 'bread'), named after the green color of the pea paste, which resembles the bird's plumage.