'Meantime' vs. 'Meanwhile'

There are so many words to learn on other pages of this website, but in the meanwhile, let's talk about a pair of words you probably know very well. Or should I say "in the meantime, let's talk…"? Or maybe I should say "meanwhile, let's talk…"?

Huh. Meanwhile and meantime: are they the same? Does it matter which one you use?

Both 'meantime' and 'meanwhile' have been used as adverbs, as in "meanwhile/meantime, down at the farm…," since the late 1500s.

Have no fear. We're here to give you the lowdown:

Usage of Meanwhile and Meantime

Meantime and meanwhile have both been used as nouns in the prepositional phrase "in the meanwhile/meantime" since the 1300s—which is from the time of their lexical infancy. (They also both appear in other phrases, like "for the meanwhile/meantime.") Both have been used as adverbs, like in "meanwhile/meantime, down at the farm…," since the late 1500s. They've been interchangeable for pretty much all of their long histories. But that doesn't mean they don't each have their favorite territory.

Meantime is the one that's usually used as a noun (that is, as the object of the preposition in phrases like "in the meantime" and "for the meantime."):

The company will be put up for auction…. In the meantime, the company will use two loans … to help keep the lights on.
— Maya Kosoff, Vanity Fair, 10 June 2016

The great majority of times meantime is seen in published, edited text, it's in exactly that context: as a noun, in the phrase "in the meantime." It's not difficult to find examples, though, where meantime is used as an adverb:

Meantime, the Port Authority is asking the FAA for permission to collect an extra $110 million in passenger fees to pay for preliminary construction.
— Seth Barron, City Journal, Winter 2016

Shakespeare liked to use meantime this way, as when King Lear in the eponymous 1608 play said, "Meantime we shall express our darker purpose."

But the usual choice for the role of adverb is meanwhile:

He performs his signature stunt several times with formidable skill, all in full view of the camera with no cuts. Meanwhile, mere feet away, a young woman paces the parking lot, talking on her cell phone.
— Joe Blevins, A.V. Club, 14 July 2016

But, again, atypical examples are not hard to find:

But since the satellite trackers still have another year of battery life, the team is hoping to learn much more in the months to come. In the meanwhile, enjoy some lovely photos of whale sharks from the study….
— Maddie Stone, Gizmodo, 27 June 2016

"In the meanwhile" has been accused of being "unidiomatic" (i.e. of sounding weird), but it isn't so unidiomatic that native speakers instinctively avoid it. If you use it, there's no reason you should stop.

But if you want to use this pair of words in the ways they're most often used and need help remembering which goes where, you can think of this sentence:

In the time it takes to say "in the meantime," you could just as well say "meanwhile."

But really, the most efficient way to deal with the pair is to use whichever you prefer wherever you prefer it.