from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A rapid, involuntary, oscillatory motion of the eyeball.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. rapid involuntary eye movement, usually lateral
from the GNU version of the Collaborative International Dictionary of English
- n. A rapid involuntary oscillation of the eyeballs.
from The Century Dictionary and Cyclopedia
- n. In medicine, involuntary lateral oscillatory (sometimes rotatory, rarely vertical) motion of the eyes.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. involuntary movements of the eyeballs; its presence or absence is used to diagnose a variety of neurological and visual disorders
New Latin, from Greek nustagmos, drowsiness.(American Heritage® Dictionary of the English Language, Fourth Edition)
First attested in 1798. From New Latin nystagmus, from Ancient Greek νυσταγμός (nustagmos, "nodding, drowsiness"), from νυστάζω (nustazō, "nod, be sleepy"). (Wiktionary)