infectious disease, late 14c., from Latin tetanus "tetanus," from Greek tetanos "tetanus, muscular spasm," literally "a stretching, tension," from teinein "to stretch" (from PIE root *ten- "to stretch"); "so called because the disease is characterized by violent spasms and stiffness of the muscles" [Barnhart]. Related: Tetanoid (adj.).
Others are reading
Definitions of tetany from WordNet
clinical neurological syndrome characterized by muscular twitching and cramps and (when severe) seizures; associated with calcium deficiency (hypoparathyroidism) or vitamin D deficiency or alkalosis;