noun
swiftlet
A type of bird that builds nests in caves, known for its edible nests used in bird's nest soup.
アナツバメの巣は高級食材として知られている。
Swiftlet nests are known as a luxury food ingredient.
ツバメ is the common swallow, while アナツバメ specifically refers to swiftlets, which are related but distinct.
Compound of 穴 (ana, 'hole') and 燕 (tsubame, 'swallow'), referring to the bird's habit of nesting in caves.