Alz·hei·mer's disease (ältshī-mərz, ălts-, ôlts-, ôlz-)
A degenerative disease of the brain, occurring chiefly in elderly people and characterized by disorientation, memory failure, speech disturbances, and the progressive loss of mental capacity. It is associated with the formation of beta-amyloid plaques and neurofibrillary tangles in the cerebral cortex and loss of neurons.
[After Alois Alzheimer (1864-1915), German neurologist.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.