开司米 is a phonetic loan from English cashmere - itself a corruption of Kashmir
克什米尔, the Himalayan region whose goats produce the soft underwool used for the fabric. The characters are pure sound:
开 (open) +
司 (manage) +
米 (rice). The newer rendering
羊绒 ('goat down') is the native Chinese term and is now equally common in product labeling.
