Wordnet 3.0
ADJECTIVE (1)
1.
of or relating to or near the small of the back and the back part of the pelvis between the hips;
The Collaborative International Dictionary of English v.0.48:
Lumbosacral \Lum`bo*sa"cral\, n. [L. lumbus loin + E. sacral.]
(Anat.)
Of or pertaining to the loins and sacrum; as, the lumbosacral
nerve, a branch of one of the lumber nerves which passes over
the sacrum.
[1913 Webster]
WordNet (r) 3.0 (2006):
lumbosacral
adj 1: of or relating to or near the small of the back and the
back part of the pelvis between the hips