egg-cup n.

"the body formed in the females of all animals (with the exception of a few of the lowest type) in which by impregnation the development of the fetus takes place," mid-14c., egge, mostly in northern England dialect, from Old Norse egg, from Proto-Germanic *ajja(m) (source also of Old Saxon, Middle Dutch, Dutch, Old High German, German ei, Gothic ada), probably from PIE *owyo-/*oyyo- "egg" (source also of Old Church Slavonic aja, Russian jajco, Breton ui, Welsh wy, Greek ōon, Latin ovum); possibly derived from root *awi- "bird."

This Norse-derived northern word vied in Middle English with native cognates eye, eai, from Old English æg, until finally displacing the others after c. 1500. Caxton (15c.) writes of a merchant (probably a north-country man) in a public house on the Thames who asked for eggs:

And the goode wyf answerde, that she coude speke no frenshe. And the marchaunt was angry, for he also coude speke no frenshe, but wolde have hadde egges, and she understode hym not. 

She did, however, recognize another customer's request for "eyren." Used of persons from c. 1600. Bad egg in the figurative sense is from 1855; bad eggs aren't always obvious to outward view (there was an old proverb, "bad bird, bad egg"). To have egg on (one's) face "look foolish" is attested by 1948.

[Young & Rubincam] realize full well that a crew can sometimes make or break a show. It can do little things to ruin a program or else, by giving it its best, can really get that all-important rating. They are mindful of an emcee of a variety show who already has been tabbed "old egg in your face" because the crew has managed to get him in such awkward positions on the TV screen. [Billboard, March 5, 1949] 

We don't have egg on our face. We have omelet all over our suits. [NBC News anchor Tom Brokaw, some time past 3 a.m. ET on Nov. 8, 2000, after the U.S. television networks called a winner, then retracted the call, in the Bush-Gore presidential election]

 Eggs Benedict is attested by 1898; various Benedicts are cited as the eponym, and the dish itself is said to have originated in the Waldorf-Astoria or Delmonico's, both in New York. The figure of speech represented in to have (or put) all (one's) eggs in one basket "to venture all one has in one speculation or investment" is attested by 1660s. The conundrum of the chicken (or hen) and the egg is attested from 1875.

Bumble, bramble, which came first, sir,

Eggs or chickens? Who can tell?

I'll never believe that the first egg burst, sir,

Before its mother was out of her shell.

[Mary Mapes Dodge, "Rhymes and Jingles," N.Y., 1875]

"small vessel used to contain liquids generally; drinking vessel," Old English cuppe, Old Northumbrian copp, from Late Latin cuppa "cup" (source of Italian coppa, Spanish copa, Old French coupe "cup"), from Latin cupa "tub, cask, tun, barrel," which is thought to be cognate with Sanskrit kupah "hollow, pit, cave," Greek kype "gap, hole; a kind of ship," Old Church Slavonic kupu, Lithuanian kaupas "heap," Old Norse hufr "ship's hull," Old English hyf "beehive." De Vaan writes that all probably are from "a non-IE loanword *kup- which was borrowed by and from many languages."

The Late Latin word was borrowed throughout Germanic: Old Frisian kopp "cup, head," Middle Low German kopp "cup," Middle Dutch coppe, Dutch kopje "cup, head." German cognate Kopf now means exclusively "head" (compare French tête, from Latin testa "potsherd").

Used of any thing with the shape of a cup by c. 1400; sense of "quantity contained in a cup" is from late 14c. Meaning "part of a bra that holds a breast" is from 1938. Sense of "cup-shaped metal vessel offered as a prize in sport or games" is from 1640s. Sense of "suffering to be endured" (late 14c.) is a biblical image (Matthew xx.22, xxvi.39) on the notion of "something to be partaken of."

To be in one's cups "intoxicated" is from 1610s (Middle English had cup-shoten "drunk, drunken," mid-14c.). [One's] cup of tea "what interests one" is by 1932, earlier used of persons (1908), the sense being "what is invigorating." Cup-bearer "attendant at a feast who conveys wine or other liquor to guests" is from early 15c.