serine (n.)

late 14c., sarge, in reference to a woolen cloth in use in the Middle Ages, apparently of a coarse texture, from Old French sarge, serge (12c.), Medieval Latin sargium, sargea "cloth of wool mixed with silk or linen,"  from Vulgar Latin *sarica, from Latin serica (vestis) "silken (garment)," from serica, from Greek serikē, fem. of serikos "silken" (see silk).

In later use of a kind of strong, durable fabric, originally woven of silk, later of worsted. The French word is the source of German sarsche, Danish sarge, etc. Also as a verb. Related: Serger.