en.wikipedia.org/wiki/Cartesian_coordinate_system

A Cartesian coordinate system is a coordinate system that specifies each point
uniquely in a .... A plane with x- and y-**axes defined** is often referred to as the
Cartesian plane or xy-plane. .... In such a 2D diagram of a 3D coordinate system,
the **z**-**axis** would appear as a line or ray pointing down and to the left or down and
to the ...

www.pcmag.com/encyclopedia/term/54951/x-y-z-matrix

A three-dimensional structure. The x-**axis** and y-**axis** represent the first two
dimensions; the **z**-**axis**, the third dimension. In a graphic image, the x and y
denote ...

www.calpoly.edu/~elovagli/HTML/concepts_01.htm

Maya (and virtually all 3-D programs) **define** virtual 3-dimensional space with a ...
In Maya, X is the **axis** that goes side to side, Y is up to down and **Z** is forward to ...

math.la.asu.edu/~surgent/mat267/examples/xyz_coordinate_system_2.pdf

Example 1.1: Sketch the point (2,3,5) on an **xyz**-coordinate **axis** system. Solution:
..... of the set of points (ordered n-tuples) for which a function is **defined** is called.

english.stackexchange.com/questions/56472/x-y-z-horizontal-vertical-and

Jan 31, 2012 **...** It says they are rarely used, but I doubt there are many other alternative terms,
other than **Z**-**axis**, depth, and so on; they're the most appropriate ...

www.quora.com/How-do-you-represent-Roll-Pitch-Yaw-in-terms-of-X-Y-Z-axes-in-space

Well concept is so easier just imagine daily life examples. Roll: you can see in
above image ... One set of **axes** is fixed to the spacecraft and roll/pitch/yaw are
**defined** in relationship to these. Other **axes** can be **defined**, as well. For example,
you ...

www.dictionary.com/browse/z-axis

**Z**-**axis definition**, (in a three-dimensional Cartesian coordinate system) the **axis**
along which values of **z** are measured and at which both x and y equal zero.