The interest in the French dictionary (ok, boronia, dictionnaire--belated welcome, by the way) led me to try and find other words that are the same or very similar in both languages. One I put in was fiche. One of the def.'s was fiche dactyloscopique. I googled dactyloscope on a guess, and was led to dactyloscopy: n. comparison of fingerprints for identification. (From The Dictionary of Difficult Words.) Then, I found:
dactyl
n. metrical foot comprising one long followed by two short syllables; Zoology, digit. dactylate, a. like a finger. dactylic, a.; n. verse of dactyls.Same dictionary:
http://www.tiscali.co.uk/reference/dictionaries/difficultwords/data/d0004218.html

My question: how did dactyl come to have these two seemingly unrelated meanings?

The OED lists the origin as:

[ad. (perh. through F. dactyle) L. dactylus, a. Gr. d0jstko|, a finger, a date, a dactyl (from its 3 joints).]

(Sorry, I don't know how to get the Greek characters to copy properly)

The OED contains 36 words with dactyl*.
The one I found most interesting was: dactylology
[f. Gr. d0jstko| finger + -kocia discourse: see -logy.]
‘Finger-speech’; the art of ‘speaking’ or communicating ideas by signs made with the fingers, as in the deaf-and-dumb alphabet. (Formerly chirology.)

Since you also mentioned French:
dactylographie (nf) - typing, typewriting

Bonjour, Jackie--

dactyl
\Dac"tyl\, n. [L. dactylus, Gr. da`ktylos a finger, a dactyl. Cf. Digit.] 1. (Pros.) A poetical foot of three sylables (--- [crescent] [crescent]), one long followed by two short, or one accented followed by two unaccented; as, L. t["e]gm[i^]n[e^], E. mer\b6ciful; -- so called from the similarity of its arrangement to that of the joints of a finger. [Written also dactyle.]
2. (Zo["o]l.) (a) A finger or toe; a digit. (b) The claw or terminal joint of a leg of an insect or crustacean.
Source: Webster's Revised Unabridged Dictionary, © 1996, 1998 MICRA, Inc.

Remember dactyls from "Listen my children and..." or "higgledy-piggledy"?
Who would've thought they had any relation to fingers? That must mean that trochee comes from a word meaning thumb.

So where do the words iamb, spondee, troche and anapest come from?
And since we've been "digitizing", a further question: why to we call it a metrical "foot"?

Merci, les deux. Three joints, three syllables. Got it!
Yes, 'gator, I remember those poems--I've always loved anything in triple time.

anapaest = struck back or rebounding, because it's a reversed dactyl

iamb = an iamb, sorry; neither Greek nor English dictionaries show any other root it might be derived from

spondee = suitable for solemn libations

trochee = running

I can never remember which is which of these, and always when I reread them grasp at the fact that 'spondee' is a spondee, and see if I can pin them down that way. Illusory.

Dear Jackie: If you look at a finger, the bone nearest the knuckle is longer than the two distal ones.
Long,short, short.

Hey, Dr. Bill, how come I only have one knuckle on my thumb? It's only bendable from just under the nail.

Dear consuelo: If you mean you have only two bones in your thumb, that is something I have never seen. I have see babies with a tiny second thumb attached to base of thumb, but not capable of motion. Up in Maine I saw a guy with two index fingers on each hand but no thumb. His neighbors called him "Five finger Joe." Imagine him playing a piano. Didn't seem to bother him, although he could not touch tip of little finger with the extra index finger. I didn't ask him if he had trouble thumbing rides.

slithy asks: Remember dactyls from "Listen my children and..." or "higgledy-piggledy"?

I sure do remember the lovely double dactyls, to wit:

Higgledy piggledy
Ludwig von Beethoven
Bored by requests for some
Music to hum,

Finally answered with
Oversimplicity,
"Here's my Fifth Symphony:
Da-da-da-dum."

In fact, while I'm not real good at limericks hi Helen I did compose a d-d for the occasion of the first year of this board's existence, back in the good old days. Since I am too modest to go fiche-ing for compliments [ahem], perhaps someone else would like to post it here....

I did compose a d-d for the occasion of the first year of this board's existence. Since I am too modest to go fiche-ing for compliments, perhaps someone else would like to post it here

with pleasure, and with my compliments:

Higgledy Piggledy,
Anu Garg's AWADtalk
Celebrates one year of
Being today.

Stilling the urge to wax
Sesquipedalian,
I'll keep it short and say:
"Hip, hip, hooray!"

And as we are coming to the second anniversary, would you perhaps offer a complementary re-doubling of the dactyl to accompany that compliment?

Dear AnnaS,

I'm glad to be able to read your first-anniversary double-dactyl. How about treating us to another?

Here are a couple verses that highlight the most common varieties of metrical feet:

The iambs go from short to long,
Trochees sing a marching song,
Dactyls go dancing as light as a feather,
But the anapest’s different you see, altogether.            
(Richard Lederer)

Trochee trips from long to short;
From long to long in solemn sort
Slow Spondee stalks, strong foot!, yet ill able
Ever to come up with Dactyl's trisyllable.
Iambics march from short to long.
With a leap and a bound the swift Anapests throng.
(Samuel Taylor Coleridge)
 

Tin ear strikes again. I gather I'm meant to be able to work out what each of the feet is from these rhymes? Let's see. I can tell stressed from unstressed, so let's apply that to the first line.

Trochee trips from long to short;
S-u S u S u S

Hm, looks like cataleptic iambic tetrameter to me. So let's try a different track. I can tell open from closed syllables by looking for the presence of a final consonant.

Trochee trips from long to short;
o-o C C C o C

Nope, can't recognize any patterns there. But a "long" syllable in the classical languages is one which is either closed, or has a long vowel. Both tro- and chee- are long the way I say them, so that makes it:-

Trochee trips from long to short;
L-L L L L s L

At which point I confirm I'm not destined for a career in poetry or music, and give up once more.