Old English seam "seam, suture, junction," from Proto-Germanic *saumaz (source also of Old Frisian sam "hem, seam," Old Norse saumr, Middle Dutch som, Dutch zoom, Old High German soum, German Saum "hem"), from PIE root *syu- "to bind, sew."
Chidynge and reproche ... vnsowen the semes of freendshipe in mannes herte. [Chaucer, "Parson's Tale," c. 1386]Meaning "raised band of stitching on a ball" is recorded from 1888. Geological use is from 1590s.
1580s, from seam (n.). Related: Seamed; seaming.