Antosian silk is a material, a form of silk that is a prized commodity used to make clothing.
History and specifics[]
The larva that produces the Antosian silk weave it inside the stomachs of Antosian oxen.
In the year 2371, Elim Garak showed Grand Nagus Zek a garment made of Antosian silk. (DS9 comic: "The Nagus's New Clothes")