Apartment names have become so vague and conceptual that you expect to hear that someone’s building a new development called the Evaporate, or SkyVoo.

Quick test: Which of these is the actual name of an apartment building?

a) Clarity

b) The Gaucherie

c) Ether

d) Cielo

It’s D.

It’s one of those vague new apartment names, like the Era, the Arrive, the Chroma, the Axis, the Revel, the Mosaic, and the Uptown Lakes.

Well, perhaps that last one isn’t so vague.

It’s remarkably specific, and seems a bit dull compared with the airy nomenclature of most new prestige apartments. Why have the names gotten so conceptual, and whatever happened to apartments called the Sheltering Arms?

As for the first question: branding, of course. They’re not selling space for eating and sleeping. They’re selling a lifestyle, a modus vivendi you can slip into as easily as a key in a lock.

The brochures usually show a rooftop at dusk — it’s always 9:02 p.m. on June 20th at this apartment — and there will be pictures of a man and woman laughing on a balcony, with glasses of white wine. You will Revel in your life. You will feel as though you’ve begun a new Era. You’ve Arrived.

Not any name will do.

The address isn’t good enough, unless it’s part of the selling point. Consider Nic on Fifth. Seems plain enough, until you think about it. The building is located at Nicollet and 5th Street. So the building itself is the Nic, which is on 5th. Perhaps they have plans to build the Ollet across the street.

Nearby is the 4Marq, which is on Marquette and 4th Street. It’s 80 percent Marq, 20 percent 4th. You suspect that someone wanted to call it Marq IV, but that looks like a place where you get intravenous fluids.

Of course, not all of the names are silly or precious. The Portland Tower is, as it happens, a Tower on Portland. So there. The Opus-built tower across from the downtown library is called the 365 Nicollet, which suddenly makes all the other buildings look like poseurs in a bar who stare into their craft beers when someone elegantly dressed walks in and orders a Manhattan.

The Kraus-Anderson block — one of the more interesting collections of ordinary buildings in recent years — has a 17-story apartment called the “HQ,” which makes you snap to attention. It’s certainly better than its dullard neighbor, Centre Village, which is neither. You’re not sure if they mean “Centre” in the sense of being pretentiously French or pretentiously British, but it doesn’t matter; the building might as well have been called Tall Bed Place.

No matter how good it is, a name can’t save a lame design. In the 1970s and ’80s, names had a different flavor — the Crossings at Woodland Grove, or the Grovings at Landwood Center, or the Gerund at Crossgrove Landing. They were made-up names that reeked of prefab boring brick developments without distinction.

But most of the old buildings have names with heft and history.

In Elliot Park there’s the Monadnock, named for a New Hampshire mountain mentioned by Emerson and Thoreau. There’s the Balmoral, named after the Scottish castle where the British royal family often resides.

These names add gravity and heft to a standard apartment building, bestowing a touch of upper-class swank to an interchangeable middle-class flat.

There’s really no harm in pretentious apartment building names. If you slap something airy on a standard-issue ’60s block, no one will be fooled. Eclipse or Hello or Edition is better than a rote address, and lends some interest to the street, if only in the form of a sign.

Too bad no one builds any arms anymore, though. Possibly because it looks silly to modern eyes. Arms, as in limbs? Sheltering and protecting the residents? Surprisingly, that’s not where the name comes from.

It’s likely that it’s from tourists misunderstanding the word on English pub signs, which often bore the crest of a local noble. If one wanted to serve food fit for the ruling class, one would petition the inbred lord, and receive a royal warrant, and display the coat of arms for that house.

Many inns offered lodging as well, so people who were new to English ways associated “arms” with “lodging,” and took the term back to America for apartment buildings. That’s the most common explanation, anyway.

If someone builds a new complex that’s only garden apartments, and calls it Feet, now you’ll know why.