cupyoudaoicibaDictYouDict[cup 词源字典]
cup: [OE] Cup is a member of a large Indo- European family of words denoting broadly ‘round container’ that go back ultimately to the bases *kaup- (source of English head) and *keup-. This produced Greek kúpellon ‘drinking vessel’, English hive, and Latin cūpa ‘barrel’, source of English coop [13] (via Middle Dutch kūpe) and cooper ‘barrel-maker’ [14] (from a derivative of Middle Dutch kūpe). A postclassical by-form of cūpa was cuppa, from which came German kopf ‘head’ and English cup.
=> coop, cupola[cup etymology, cup origin, 英语词源]
cup (n.)youdaoicibaDictYouDict
Old English cuppe, from Late Latin cuppa "cup" (source of Italian coppa, Spanish copa, Old French coupe "cup"), from Latin cupa "tub, cask, tun, barrel," from PIE *keup- "a hollow" (cognates: Sanskrit kupah "hollow, pit, cave," Greek kype "a kind of ship," Old Church Slavonic kupu, Lithuanian kaupas).

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"). Meaning "part of a bra that holds a breast" is from 1938. [One's] cup of tea "what interests one" (1932), earlier used of persons (1908), the sense being "what is invigorating."
cup (v.)youdaoicibaDictYouDict
late 14c., "to draw blood by cupping," from cup (n.). Meaning "to form a cup" is from 1830. Related: Cupped; cupping.