c.1300, "overlapping plate or strip in armor" (made of metal splints), probably from Middle Low German splinte, splente "thin piece of iron," related to Middle Dutch splinte "splint," probably literally "thin piece cut off," and from a Germanic offshoot of PIE *(s)plei- "to split, splice" (see flint). Cognate with Danish splint "splinter," Swedish splint "wooden peg, wedge." Meaning "slender, flexible slip of wood" is recorded from early 14c.; specific surgical sense is attested from c.1400.