Word Origin & History
late 14c., "large snake," from L. boa, type of large serpent mentioned in Pliny's "Natural History;" origin unknown (in M.E. folk etymology associated with Gk. bous "ox"); perhaps ult. from PIE root *beu- "to swell." Extension to "snake-like coil of fur worn by ladies" is from 1836. Boa constrictor so
called from 1788.