Definitions
from The American Heritage® Dictionary of the English Language, 4th Edition
 adj. Having the shape of a cube.
 adj. Shaped similar to a cube.
 adj. Having three dimensions.
 adj. Having a volume equal to a cube whose edge is of a stated length: a cubic foot.
 adj. Mathematics Of the third power, order, or degree.
 adj. Of or relating to a crystalline form that has three equal axes at right angles to each other; isometric.
 n. Mathematics A cubic expression, curve, or equation.
from Wiktionary, Creative Commons Attribution/ShareAlike License
 adj. Used in the names of units of volume formed by multiplying a unit of length by itself twice.
 adj. Of a class of polynomial of the form
 adj. Having three equal axes and all angles 90°.
 n. A cubic curve.
from the GNU version of the Collaborative International Dictionary of English
 adj. Having the form or properties of a cube; contained, or capable of being contained, in a cube.
 adj. Isometric or monometric. See Crystallization.
 n. A curve of the third degree.
from The Century Dictionary and Cyclopedia
 Having the form of a cube.
 Solid; threedimensional: said of a unit of volume related to a unit of length of the same name as a cube is related to its edge. Thus, a cubic yard is the volume or solid contents of a cube whose edges are each a yard long. Abbreviated c.
 In algebra and geometry, being of the third order, degree, or power.
 n. In mathematics, a cubical quantic, equation, or curve.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
 adj. having three dimensions
Etymologies
Sorry, no etymologies found.
Examples

The 392 designation comes from the engine's size in cubic inches, a measurement familiar to those of us raised in the muscle car era, many of whom are the Challenger's target demographic.

To recap: Optogenetics can trigger neurons within a carefully limited area, that is, a cubic millimeter or two.

I've seen several references to a unit of energy called the cubic mile of oil (CMO).

Aluminum is cubic, which is based on squares, so Keo was right.

Halite crystallizes in the isometric (also called cubic) crystal system and when it forms crystals, it generally forms cubes.

The primary objective is to increase productivity, or pulp yield, defined as cubic meters of pulp grown per hectare of plantation.

The latter, commonly called cubic nitre or Chile saltpetre, is the kind occurring in Chile.
Commercial Geography A Book for High Schools, Commercial Courses, and Business Colleges

Cent. has a greater weight under a given volume (that is, a cubic unit of it is heavier at this temperature) than it is at any temperature either higher or lower.

Most doctors define mild neutropenia as neutrophil levels from 1000 to 1500 neutrophils per milliliter (onethousandth of a liter; also called a cubic centimeter) of blood.

It is likewise corroborated by the apparent con  version of lime and soda into potash in our calcareous caverns, and by the change of what the workmen call cubic salts, into nitrate of potash.
fbharjo commented on the word cubic
cubicle  repeated cubes
September 20, 2011
hilart commented on the word cubic
I use this word a lot at work. I drive a cement truck.
October 22, 2008