Henry Jones,
As I was reading your post I happened to have sitting next to the "McGraw-Hill Dictionary of Scientific and Technical Terms". Maybe something like that is what you're looking for.
But if you don't mind sorting through some irrelevant junk, it's hard to beat a Google Search for info on just about anything.
By the way, I looked up both your terms in that MG Tech Dictionary.
Nothing for "pure energy" although that term is usually used the context of high energy or cosmological physics. It comes from the matter-energy equality that Einstein discovered a hundred years ago. Most things in the universe today are mixtures of matter and energy. But it's thought by physicists that at the instant the universe was formed, there was no matter. It was just pure-energy. Within a small fraction of second the energy began turning into matter.
Time is a tricky one! So is its counterpart-space, or position. Physicist sort of wave their hands on these, and say "we know what we mean by time and space, and if there's ever any disagreement we'll settle it with some math!" The MG Tech Dictionary did have a definition for time, something like, "The dimension of the physical universe which at a given location in space, specifies the ordered sequence of events." Not bad.
By the way, in Einstein's first paper on his theory of relativity, which was fundamentally about time and our perception of it, did he resort to some fancy arcane definion to base his theory on? No. He talked about what it means to say "the train will arrive at the station at 7 pm". We all know what he means!
