Duality is a connection between two things where the properties of one defines the properties of the other.
Here's what comes up in Google:
1. the quality or condition of being dual.
"the novel's deep duality about human motive"
2. an instance of opposition or contrast between two concepts
or two aspects of something; a dualism.
"the photographs capitalize on the dualities of light and
dark, stillness and movement"
Also, if you look at the Wikipedia entry on Duality, just in physics, there are many kinds of duality just under physics alone. I'm not so sure this line from the article makes it past the level of "physics woo." It might be better if the article tried to talk more directly about Holographic duality, instead of trying to raise the term "duality" on a pedestal like it's some sort of Marvel Comics embodiment of "cosmic fundamentals."
It's not physics woo; the way the OP's using "duality" is common among mathematicians and physicists. The different types of duality listed in the physics and math sections of the Wikipedia article you linked to are thought of, by typical practitioners in these areas, as all being instances of a more general phenomenon. That's why these various things end up being called dualities.
That generic kind of duality is well described in the first sentence of [1], and the OP's explanation of a duality as "a connection between two things where the properties of one defines the properties of the other" is pretty obviously an attempt to convey, to a lay audience, that sense of duality.
At least within mathematics and physics, 'the properties of one defines the properties of the other' is a pretty good explanation of what's meant by 'duality'. Looking at that wiki list it explains all of the dualities I'm familiar with except (maybe?) the wave-particle duality.
Here's what comes up in Google:
Also, if you look at the Wikipedia entry on Duality, just in physics, there are many kinds of duality just under physics alone. I'm not so sure this line from the article makes it past the level of "physics woo." It might be better if the article tried to talk more directly about Holographic duality, instead of trying to raise the term "duality" on a pedestal like it's some sort of Marvel Comics embodiment of "cosmic fundamentals."http://en.wikipedia.org/wiki/Duality