This one's got a long history, so hold tight: borrowed in 1777 from Late Latin sēriceus, silken, from Medieval Latin sēricum, silk garment, silk, from the neuter of Latin sēricus, meaning both silken and Chinese, borrowed from Greek sērikos, also meaning both silken and Chinese, from Sēres, an eastern Asian people traditionally identified as referring to Han China -- as it was during the Han dynasty (roughly 200 BCE to 200 CE) that silk reached the eastern Mediterranean. Note also that sḗr became the Greek word for silkworm. Heading back up through history, there are several related words built on the seri- stem -- this happens to be the one describes something as being "like silk" instead of "made of silk." The first sense given above is mostly used in biology, especially botany.
I got to gently stroke the arctic fox pup and its sericeous brown fur.