A mock conversation from the jr. high level book What’s Darwin Got to Do With It? A Friendly Conversation About Evolution:

• Creationist: Before we get started, we’ve got to clear up some terms. Words can be used a lot of different ways.
• Evolutionist: That’s what we have dictionaries for.
• Creationist: This is a little trickier than that. like, how would you define the word “adult?”
• Evolutionist: Mature. Responsible. Grown up. Why?
• Creationist: So, when you (as a mature, responsible grown-up) want something to read, do you shop at an adult bookstore?… I don’t think so. We have the same problem here. Evolution” and “creationism” are both wagon words. “
• Evolutionist: Wagon words?
• Creationist: Yeah, you know, loaded with other stuff that comes along when you pull the handle [of a wagon].
• Evolutionist: How do you mean?
• Creationist: Well, take “evolution.” Some people talk as though all it means is “change over time.” If that were all it meant, I’d buy it.
• Evolutionist: You mean I win already?
• Creationist: No, of course not. All I’m saying is that nobody in their right mind questions that some animals have changed some through the course of their existence on earth. What I find, though, is that when I grab the [wagon] handle, all sorts of other things come along with it. Things like a belief that an unguided, purposeless process can cause the accumulation of minor changes and cascade them into major complex innovations.
• Evolutionist: What about “creationism?”
• Creationist: Well, I prefer to be called a design theorist. My major point is that some things in the natural world are so complex that it seems more likely that they were designed rather than arose by chance. Unfortunately, when I pull this handle… you find that you’re also stuck with defending a geologically young earth… and the idea that everything we see on earth was created in six calendar days.
• Evolutionist: So you’re saying that the terms are too broad?
• Creationist: Yeah. I’ve seen people use “evolution” to refer to something as simple as minor changes in bird beaks. I’ve also seen people use the term to mean the spontaneous appearance of life… its unguided creation of major innovations (like the birds themselves)… and its purposeless progression into incredible complexity (like the human brain).
• Evolutionist: And I’ve seen people use the term “creationism” for everything from a strict literal reading of Genesis… all the way to the idea that God started the ball rolling and then let nature take its course. Yeah, I guess you’re right – the terms are too broad.
• Creationist: May I suggest that we use these terms so that we don’t end up pulling more than we want?

Some working language then:

Creation or Creation-science

The belief that the earth is no more than 10,000 years old, and that all biological life forms were created in six calendar days and have remained relatively stable throughout their existence.

Intelligent Design or Design Theory

The belief that the earth and biological life owe their existence to a purposeful, intelligent creation.

Darwinism

The belief that undirected mechanistic processes (primarily random mutation and natural selection) can account for all the diverse and complex living organisms that exist. Insists that there is no long range plan or purpose in the history of life (i.e., that changes happen without intent).

Micro-evolution

Refers to minor variations that occur in populations over time. Examples include variation in moth population and finch beaks, and the emergence of different breeds of dogs.

Macro-evolution

Refers to the emergence of major innovations or the unguided development of new structures (like wings), new organs (like lungs), and body plans (like the origin of insects and birds). Includes changes above the species level, especially new phyla or classes. [species and classes are a hot – debatable – topic.]

Common Descent

The theory that all currently living organisms are descended from a common [or a few common] ancestor[s].

My Favorite

General Theory of Evolution (GTE): “the theory that all the living forms in the world have arisen from a single source which itself came from an inorganic form.”