An interesting way to look at dictionary definitions is to look at the definition by itself and see whether you can figure out the word it’s attempting to define. For example, if you see “any one of the berries, growing in clusters on a vine, and from the juice of which wine is made,” you can see that it’s defining “grape.” And “a small, typically open vessel for traveling over water, propelled by oars, sail, an engine, etc,” is clearly a “boat.”
But how about this one? “Any thing reticulated or decussated, at equal distances, with interstices between the intersections.” For most people, the only thing this brings immediately to mind is something like “huh?” It’s actually a relatively famous definition, simply because it’s so impenetrable.
Taking it step by step, “reticulated” means divided into segments. That’s sort of the same thing that “interstices between the intersections” means; an intersection is where two or more things cross (that point is “inter” or between, the “sections”). “Interstice” just means an area between marked points. So “interstices between” is redundant, and I’m not at all sure it’s possible to have intersections without interstices, so that whole phrase kind of boils down to just “intersections.”
“Intersection” is very common, and you might run across “interstice” occasionally. But “decussated” is something else again. It’s a vanishingly obscure word, but it has a very simple meaning; it’s where two things intersect crossways. That is, to “decussate” is to make an “X” shape. As for why there’s a specific word for that, your guess is as good as mine. It comes from the Latin word “decussare,” which you won’t be surprised to learn means…wait for it… “to make an X shape.”
So there you have it. “Any thing reticulated or decussated, at equal distances, with interstices between the intersections” means a thing that’s divided into sections with X shapes.” Another way to put it is this: “an arrangement or structure having the form of a net.” Now, that’s cheating a little bit because the word we’re talking about is “network,” and the unhelpful definition is from Dr Samuel Johnson’s 1755 dictionary. It’s pretty well known as one of the worst definitions ever.
But even the Oxford English Dictionary isn’t perfect; their definition of “network” is the one that relies on “net.” Seems like they could have used “lattice” or “screen,” but maybe those words just didn’t mesh.