Pronunciation: (lôr-dō'sis), [key]
1. Pathol.an abnormal forward curvature of the spine in the lumbar region, resulting in a swaybacked posture. Cf. kyphosis, scoliosis.
2. a posture assumed by some female mammals during mating, in which the back arches downward.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.