I’ve been biking quite a bit this summer, and running too, and while this is unlikely to make a kallipyg of me, one can but hope. My wife, like pretty much all lifelong high-level figure skaters, is a noteworthy kallipyg. One need not be athletic to be a kallipyg, but it seldom hurts.
It is not always easy to judge whether a person is a kallipyg. It depends on the clothing they’re wearing, but more particularly it depends on the angle you see them from. If you can see their face, for instance, you are probably not in a position to judge whether they are a kallipyg.
Does this word look like somehow it’s been cut off? It has not. Does it make you think of a pygmy? It has nothing to do with pygmies (except for inasmuch as any among them may be kallipygs, which some probably are, but not because they are pygmies). Perhaps a calliope? No, though a kallipyg may be music to the eyes of some. And the connection between kalli and calli is well made: they both come from Ancient Greek κάλλος kallos, ‘beauty’.
Some of you will see the meaning of this word coming by now. But all of you have seen it going. The pyg, you see, is from Greek πυγή pugé, ‘buttocks’. I think many of you know the word callipygian, which means ‘having beautiful buttocks’. It comes from an epithet for Aphrodite: καλλίπυγος, an adjective meaning ‘callipygian’ which, as a substantive used as an epithet, could be rendered as “sweetcheeks” or “the one with the nice bum.” (“You know, Aphrodite, the one with the buns.”)
Well, kallipyg is a rather less common word, but it comes from the same source, and it’s a noun for a callipygian person. If you want to say it out loud, the stress is on the beginning – although we could say the weight is on the end.
Sesquiotica 
Aphrodite did indeed have a beautiful arse. So much so that a city, El Arish, is named after it. Arish is probably derived from Hittite arrash (buttock) but seems cognate with Greek orros (rump, base of spine) and Germanic words like English arse.
Much of the rest of her body is described in this Limerick with end notes:
The goddess we call Aphrodite
Is not just an old Grecian deity.
The Phoenicians did make
Her a map. It’s not fake.
Her body is cartograffiti.
The Punic war destroyed her face, 1
The Romans left nary a trace.
But her hair is still there,
In Sahara, that’s where. 2
And her chin’s a Tunisian place. 3
Mt. Atlas is her first verTebra. 4
Her backbone is now Gulf of Sidra. 5
Her heart is in Libya, 6
Her left leg, Somalia. 7
Her breast is in Chad wearing no bra. 8
The Greeks called her liver Egypt,an’ 9
Her kidney was Biblical Goshen. 10
She’s bent at her waist,
Now Misr-ably placed. 11
The Red Sea was her menstruation 12
As a kid I did think the Red Sea
Was an English map typo: lost E,
From Reed Sea in Hebrew.
But that could not be true,
Mare Rubrum ’twas Latin, B.C.
Aphrodite with Hermes did sin,
We know this is true ’cause within
Her “snatch” we call Sinai 13
His “zaiyin” does still lie. 14
It’s known as the desert of Zin.
Anthropomorphic maps were made by configuring the gigantic virtual body of a god or goddess over the area to be mapped. The name of each body part became the name of the area under that part. This produced a scale 1:1 map-without-paper on which each place name indicated its approximate location, direction and size with respect to every other place on the same map whose name was produced this way.
1 The Romans destroyed Carthage during the 3rd Punic War.
In Hebrew, “face” is PaNim.
2 Hebrew Sa3aR = hair (using 3 for the aiyin).
3 Tunis is a reversal of SaNTir = chin in Hebrew.
4 Atlas = cervical vertebra supporting the skull.
5 In Hebrew, SHiDRa is spine, backbone.
6 The Semitic term for “heart” is LeB.
7 In Hebrew, “left” is S’MoL.
8 In Hebrew, “breast” is SHaD.
9 As in ancient Greek hepato- “liver”.
10 The ancient shin had a T-sound. SHoR = ox was ToR as in Taurus. Gimel had a K-sound in other languages: GaMaL = camel. So, GoSHeN sounded like QTN, as in QiTNiot = beans. Goshen was her bean-shaped kidney, so Ashkenazi Jews do not eat beans on Passover. Cotton was exported from QTN / Goshen. The cotton genus is Gossypium. Compare gossamer T => a glottal stop. Treating aleph as CHS, Sinai sounded like SNCHs, a reversal of K’NiSah = entrance (to her body).
14 Zaiyin means “weapon” in Hebrew. It is also a euphemism for the male member.
End notes 10 through 13 became garbled. They should look like this:
10 The ancient shin had a T-sound. SHoR = ox was ToR as in Taurus. Gimel had a K-sound in other languages: GaMaL = camel. So, GoSHeN sounded like QTN, as in QiTNiot = beans. Goshen was her bean-shaped kidney, so Ashkenazi Jews do not eat beans on Passover. Cotton was exported from QTN / Goshen. The cotton genus is Gossypium. Compare gossamer from Latin cotton+sea = foam (Greek aphros).
11 Arabic Misr & Hebrew MiTZRaim are derived from the Semitic term for narrow, TZaR. The waist should be the narrow part of the body.
12 In Latin, the Red Sea was Mare Rubrum. In Hebrew, the Red Sea is “Yam SooF” = Sea of Reeds. SooF is a reversal of the sounds in peh-sof PoS, Hebrew for the female pudenda.
13 In Hebrew, Sinai is spelled SiNi without an aleph but is pronounced as if had an aleph after the nun. The ancient sound of aleph changed from CHS/GHT => T => a glottal stop. Treating aleph as CHS, Sinai sounded like SNCHs, a reversal of K’NiSah = entrance (to her body).