silk

From Middle English silk, sylk, from Old English sioloc, seoloc, seolc. Its immediate source is uncertain, but it likely reached English via Baltic trade routes, ultimately tracing back through Late Latin sēricus and Ancient Greek σηρικός (sērikós) to an Oriental language, represented today by Chinese 絲/丝 (sī, "silk").

The word displaced the earlier Old English term sīde, which had meant the same thing, suggesting this trade-borrowed word won out over the native one.

It's a doublet of seric and serge, both of which trace back to the same Greek σηρικός root, and it shares cognates like Old Norse silki, Danish silke, Swedish silke, and Russian шёлк (šolk).