Here's a breakdown:
* Old French: The word "silk" came from the Old French word "selic".
* Middle English: This word then entered Middle English as "silk".
The ultimate origin of "silk" is believed to be from the Latin word "sericum", which referred to the fabric itself. The word "sericum" in turn is believed to have come from the Greek word "sērikós"** (meaning "of silk").
It's interesting to note: The Greeks and Romans learned about silk through their trade with the Silk Road, which connected the East and West for centuries. The source of silk was a mystery for a long time, and the fabric was considered a luxury good. It was only later that the source of silk was discovered to be China, where the silkworm was domesticated and the art of silk production was developed.