I want to explain perfect competition to students using a few practical examples without going into much of the theory. But I want it to be theoretically accurate and I don't want to claim that those are examples of 'perfect competition'. I am thinking about calling it 'near perfect competition', but I wonder if there is a conventional term for a market that is close to perfect competition. This wikipedia article mentions 'close-to-perfect competition' but I'm not sure if that's a conventional term.
I don't think there is a standard term for what you'd want to refer to. I'd consider the following good candidates though:
I do not have a special term, but I give this analogy:
We know what a triangle is. But in the real world, it is impossible to draw a perfect triangle and there do not exist examples of perfect triangles.
Similarly, we have just learnt what perfect competition is. But in the real world, there do not exist examples of perfect competition. Nonetheless, here are some examples of real-world markets that come "close to" perfect competition ...
We stress that these markets are not actual examples of perfect competition. (To repeat, such examples do not exist.) Instead, these are merely examples that come "close to" perfect competition.