I stumbled on this while looking for something else. I found it interesting.Hope you do too.

http://www.insects.org/ced4/etymology.html

Hmm, I'm going to be so bold as to disagree with both of them. I've always thought that it must be because the majority of the most visible have a lot of yellow, butter color.

So do butterflies really hang around milk churns and butter? And more so than normal flies?

I haven't seen a milk churn for years, but know a dairy farmer I can ask if nobody else knows.

the majority of the most visible have a lot of yellow, butter color

Maybe Jackie, but we'd have to know which species were most prevalent when the term was first coined. I certainly wouldn't say most present-day English butterflies have a lot of buttery colour about them, for instance.

Here's what Random House has to say:

http://www.randomhouse.com/wotd/index.pperl?date=20010104

I wonder if anyone has considered the early usage might have derived from its changeling status, surely the most distinctive feature observable in all differently colo(u)red butterlies? In other words, as cream was seen to turn to butter, so the strange little pupae is seen to turn to this amazingly different flying creature...

(all idle and unproveable speculation of course!)

Thank you, Anna! Good heavens, I had no idea that I might have had an actual idea, there.

And, mav...I just lurve your...mind!

Reminds me of joke about an Englishman, a Frenchman and a German who were arguing about who had the best language. (This joke is funnier when spoken aloud.)

The Englishman asserted that his language was superior. Seeing a butterfly alight on a branch, he remark, "For example, our word for this lovely creature is 'butterfly.' Did you ever hear a word so lovely? So perfectly delicate, just like the creature itself."

"Ah," said the Frenchman. "Ze 'butterfly' is indeed a lovely word, but our word is even more exquisite: 'Papillon.'" He repeated the word reverently. "'Papillon.' Did you ever hear such music?"

The German spoke up: "Hey! What's wrong with 'schmetterling'?"

Normally, I don't think German sounds so great, but this time I have to agree, what IS wrong with Schmetterling? It rolls quite nicely on the tongue. In fact, Schmetterling and Entschuldigung are two of my favourite words!

Schmetterling and Entschuldigung are two of my favourite words!

I'll go with you as regards schmetterling boronia - jury's out (and down the pub) on entschuldigung though.

Talking great-sounding words from other tongues, I always had a soft spot for the Dutch window-sill: fensterbank. A lot better than our version.

Well technically there is nothing wrong with schmetterling, but it isn't quite as sonorous as papillon, and the "schm-" sound can be rather comic. I do like fensterbank! One of my favorite German words is their word for porcupine, although I can't spell it correctly -- "schtockelschwein," or "prickly pig."

the "schm-" sound can be rather comic.

You're just ticked because you can't say, "Schmetterling, shmetterling!"

Besides, what's wrong with having comic connotations in the word for butterfly?

I always had a soft spot for the Dutch window-sill: fensterbank. A lot better than our version.

If we're looking at Dutch, my favourite has to be sinnasappelsap (probably misspelled here, and sounding the best when liltingly mispronounced). It's the word for orange juice, and compares nicely to German - Chinaapfelsaft (China-apple juice).

my favourite has to be sinnasappelsap (probably misspelled here, and sounding the best when liltingly mispronounced)

"De sinnasappelsap is op de fensterbank"

Hmmm!

Hi, Alex. I don't speak German, but today I learned a phrase they have: "Error! - said the hedgehog, and dismounted from the cactus."