lateral curvature of the spine, 1706, medical Latin, from Greek skoliosis "crookedness," from skolios "bent, curved," from PIE root *skel- "bend, curve," with derivatives referring to crooked parts of the body (as in Greek skelos "leg, limb; Latin scelus "malice, badness, crime;" Old High German scelah, Old English sceolh "oblique, curved, squinting;" Albanian çalë "lame"). Related: Scoliotic.