One of three axes in a three-dimensional Cartesian coordinate system. (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 "z-axis" in a sentence
"Maybe with another linear cam in the z-axis (assuming the rods are in the x-y plane), or with levers, gears, axles, something."
"So maybe the z-axis could be “treatment”. scott Says:"
"If this were three-dimensional, you could have a z-axis labeled “alcohol ingested.”"