golf (n.)youdaoicibaDictYouDict[golf 词源字典]
mid-15c., Scottish gouf, usually taken as an alteration of Middle Dutch colf, colve "stick, club, bat," from Proto-Germanic *kulth- (cognates: Old Norse kolfr "clapper of a bell," German Kolben "mace, club, butt-end of a gun"). The game is from 14c., the word is first mentioned (along with fut-bol) in a 1457 Scottish statute on forbidden games (a later ordinance decrees, "That in na place of the realme thair be vsit fut-ballis, golf, or vther sic unprofitabill sportis" [Acts James IV, 1491, c.53]). Despite what you read on the Internet, "golf" is not an acronym. Golf ball attested from 1540s; the motorized golf-cart from 1951. Golf widow is from 1890.
Oh! who a golfer's bride would be,
Fast mated with a laddie
Who every day goes out to tee
And with him takes the caddie.

["The Golf Widow's Lament," in "Golf," Oct. 31, 1890]
[golf etymology, golf origin, 英语词源]
lad (n.)youdaoicibaDictYouDict
c. 1300, ladde "foot soldier," also "young male servant" (attested as a surname from late 12c.), possibly from a Scandinavian language (compare Norwegian -ladd, in compounds for "young man"), but of obscure origin in any case. OED hazards a guess on Middle English ladde, plural of the past participle of lead (v.), thus "one who is led" (by a lord). Liberman derives it from Old Norse ladd "hose; woolen stocking." "The development must have been from 'stocking,' 'foolish youth' to 'youngster of inferior status' and (with an ameliorated meaning) to 'young fellow.'" He adds, "Words for socks, stockings, and shoes seem to have been current as terms of abuse for and nicknames of fools." Meaning "boy, youth, young man" is from mid-15c. Scottish form laddie, a term of endearment, attested from 1540s.
-y (3)youdaoicibaDictYouDict
suffix in pet proper names (such as Johnny, Kitty), first recorded in Scottish c. 1400; according to OED it became frequent in English 15c.-16c. Extension to surnames seems to date from c. 1940. Use with common nouns seems to have begun in Scottish with laddie (1546) and become popular in English due to Burns' poems, but the same formation appears to be represented much earlier in baby and puppy.