"full of turns and curves," 1570s, from Latin sinuosus "full of curves, folds, or bendings," from sinus "curve, fold, bend" (see sinus). Related: Sinuously; sinuousness.
Sinon
Sinophobe
sinsemilla
sinter
sinuate
sinuous
sinus
sinusitis
sinusoid
Siouan
Sioux