The highest point, as of excellence or achievement; the ultimate.(noun)
The most profound degree, as of a condition or quality.(noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "ne plus ultra" in a sentence
"Those who thought about the matter at all took Owen's osteological extravaganzas for the ne plus ultra of morphological speculation."