For most of you, the title of this article does not come as a shock. I could have said, “Words that Look Like They Mean the Same Thing Often Don’t” but that’s probably unclear. In the words of Inigo Montoya, “Let me ‘splain.” Then I’ll “sum up.”
Recently, I was was standing at the bathroom sink in my bedroom (weird, right? My bathroom sink really is in my bedroom) when my husband, Bill, walked in. As he was about to say something, the light in the ceiling fan flickered and I looked up at it.
Bill: Yeah, I know. It’s going bad.
Me: Good, then I’m not having a stroke.
Bill: No, you’re not having a stroke. We need to get a new light for it.
Me: We have lots of fluorescents in the garage.
Bill: No, it needs a round one.
Me: We have lots of round fluorescents in the garage.
Bill: Not like this one.
He takes the cover off and I see that it is CIRCULAR, not round. (Which I should have known, because I installed the darn thing.)
See what I mean about words and meanings? When you describe a ball, do you call it circular or round? Probably round, but circular would not be wrong, just not as descriptive as round. If you really wanted to nail it, you would call a ball spherical, but only if your audience had successfully navigated elementary school (which I assure you, I have).
To sum up: If you needed to differentiate between a round globe-shaped light bulb and a circular, tube-shaped light bulb, which word would you use? Probably circular.