Wordnet 3.0
NOUN (1)
1.
abnormal loss of bony tissue resulting in fragile porous bones attributable to a lack of calcium;
most common in postmenopausal women;
The Collaborative International Dictionary of English v.0.48:
Osteoporosis \Os`te*o*po*ro"sis\, n. [NL.; osteo- + Gr. po`ros
pore.] (Med. & Physiol.)
An absorption of bone so that the bone tissue becomes
unusually porous. It occurs especially in elderly men and
postmenopausal women, and predisposes the elderly to
fractures of the bones.
[Webster 1913 Suppl. +PJC]
WordNet (r) 3.0 (2006):
osteoporosis
n 1: abnormal loss of bony tissue resulting in fragile porous
bones attributable to a lack of calcium; most common in
postmenopausal women