The Maven’s Word of the Day from Random House has some (albeit sketchy) information on the term. Here’s an extract:
I searched in vain in every slang book we’ve got here, in the OED, in Noah Webster’s original dictionary, in the Century Dictionary, several other American dictionaries small and large, and in many German dictionaries. What I came up with was the combining form mentioned above, the noun Schnickschnack, the verb schnicken, and three citations from Dr. Jonathan Lighter’s slang files--two for the spelling schnickelfritz and one for schnigglefritz. So, all I can do is speculate, and hope my guess is close.
In most of the larger bilingual German-English dictionaries, you’ll find the word Schnickschnack, which has a cline of meanings from ‘chit-chat’ through ‘tittle-tattle’ to ‘twaddle’ and ‘nonsense’. The monolingual Wahrig Deutsches Wörterbuch says the noun is a doubling of Schnack which also means ‘chit-chat’ or ‘drivel’. The informal verb schnicken means ‘to jerk’ or ‘to seize’ and implies fast, sudden, choppy movements. Somewhere in there, I think, the idea of the “schnickel” part referring to chatterboxes or impulsive people is confirmed.
Oh, and here’s the entry in Dictionary of American Regional English, which I’ve just fortuitously found linked elsewhere. I thought at first that the whole of DARE had come online. Alas no!
DARE entry
schnickelfritz n Also s(ch)nicklefritz, snicke(l)tyfritz, snigglefritz [Perh < Ger dial Schnickel, Schniggel little boy ‘ s penis + the common name Fritz] Cf hanswurst A mischievous little boy; a scamp—usu used endearingly; by ext, a sweetheart.[1872 Galaxy 14.105, No name, unless matched by deeds, can be despotic in the arena of business. If there be force and courage behind it, Ichabod Snicklefritz—certainly not a title to melt the muses . . would be esteemed and honored of his kind.] 1905 DN 3.65 eNE, Snicklefritz, snigglefritz. . . About the same as skeezicks. 1916 DN 4.281 NE, Snicketyfritz, snickeltyfritz. = snigglefritz. . . [DN Ed: The latter also in Ill.] 1967 DARE (Qu. AA3, Nicknames or affectionate names for a sweetheart) Inf CA4, Schnickelfritz. 1973 DARE File swPA (as of 1920s), Snickle-fritz. . . Endearing epithet for a child. 1975 Studies in Honor of Kasten 30 swIL, Schnicklefritz, snicklefritz [< Schnickele + Fritz]: term of endearment to small male children ( “ little guy “ ). 1983 DARE File ceWI, Snicklefritz . . usually a little rascal. 2000 DARE File seWI (as of c1950), When we visited my Uncle Valentine on his farm, he often greeted my brother with, “ Ah, there ‘ s the little Schnickelfritz! “ This was said affectionately, but reflected also his opinion that my brother was something of a scamp who frequently “ got into things “ . Ibid ceWI (as of c1955), When I was growing up in Oshkosh, people used to call a little kid a schnickelfritz as an endearment. Ibid Detroit MI (as of c1950), My father ‘ s term for a small child was schnickelfritz; his parents were from the German community in St. Louis. 2000 DARE File—Internet MN [Winona Post], Rediscovering Schnickelfritz . . Schnickelfritz was the moniker adopted by Freddie Fisher, a musician originally from Iowa. . . [H]is band [was] a forerunner of the Spike Jones type of entertainers. . . Schnickelfritz . . signed a contract for a movie in the late 1930s.
