英语词源字典 - 在线词源网站

Betsy [Betsy 词源字典]: fem. pet name, a diminutive of Bet, itself short for Elizabet or Elizabeth. Betsy as the typical a pet name for a favorite firearm is attested in American English by 1856 (compare Brown Bess, by 1785, British army slang for the old flintlock musket).[Betsy etymology, Betsy origin, 英语词源]
Betty: fem. pet name, from Bet, shortened from Elizabeth, + -y (3).
bunny (n.): 1680s, diminutive of Scottish dialectal bun, pet name for "rabbit," previously (1580s) for "squirrel," and also a term of endearment for a young attractive woman or child (c. 1600). Ultimately it could be from Scottish bun "tail of a hare" (1530s), or from French bon, or from a Scandinavian source. The Playboy Club hostess sense is from 1960. The Bunny Hug (1912), along with the foxtrot and the Wilson glide, were among the popular/scandalous dances of the ragtime era.
grand-: a special use of grand (adj.) in genealogical compounds, originally with the sense of "a generation older than," first attested c. 1200, in Anglo-French graund dame "grandmother," also grandsire (late 13c.), from such use of Old French grand-, which perhaps is modeled on Latin avunculus magnus "great uncle." The partly-anglicized grandmother, grandfather are from 15c. Other such words in European languages are formed with the adjectives for "old" or "best" (Danish bedstefar) or as diminutives or pet names (Greek pappos, Welsh taid). The French formation also is the model for such words in German and Dutch. Spanish abuelo is from Latin avus "grandfather" (from PIE *awo- "adult male relative other than the father;" see uncle), via Vulgar Latin *aviolus, a diminutive or adjective substitution for the noun.

The extension of the sense to corresponding relationships of descent, "a generation younger than" (grandson, granddaughter) is from Elizabethan times. The inherited PIE root, *nepot- "grandchild" (see nephew) has shifted to "nephew; niece" in English and other languages (Spanish nieto, nieta). Old English used suna sunu ("son's son"), dohtor sunu ("son's daughter").
lovey: affectionate pet name, 1731, from love (n.) + -y (3). Extended form lovey-dovey attested from 1819 (n.), 1847 (adj.).
mollycoddle (v.): also molly-coddle, 1870, from a noun (1833) meaning "one who coddles himself," from Molly (pet name formation from Mary), which had been used contemptuously since 1754 for "a milksop, an effeminate man," + coddle (q.v.). Related: Mollycoddled; mollycoddling.
piggy-wiggy: "A pet name for a pig; = piggy", Mid 18th cent. Reduplication (with variation of initial consonant) of piggy.
hypocoristic: "Denoting or of the nature of a pet name or diminutive form of a name", Mid 19th century: from Greek hupokorisma, from hupokorizesthai 'play the child', from hupo 'under' + korē 'child'.