(n. pl.) A disease which affects children, and which is characterized by a bulky head, crooked spine and limbs, depressed ribs, enlarged and spongy articular epiphyses, tumid abdomen, and short stature, together with clear and often premature mental faculties. The essential cause of the disease appears to be the nondeposition of earthy salts in the osteoid tissues. Children afflicted with this malady stand and walk unsteadily. Called also rachitis.