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c.1300, wan-towen, "resistant to control; willful," from Middle English privative prefix wan- "wanting, lacking" (from Old English wan "wanting;" see wane) + togen, past participle of teon "to train, discipline;" literally "to pull, draw," from Proto-Germanic *teuhan (cf. Old High German ziohan "to pull;" see tug). The basic notion perhaps is "ill-bred, poorly brought up;" cf. German ungezogen "ill-bred, rude, haughty," literally "unpulled."
As Flies to wanton Boyes are we to th' Gods, They kill vs for their sport. [Shakespeare, "Lear," 1605]Especially of sexual indulgence from late 14c. The only English survival of a once-common Germanic negating prefix still active in Dutch (cf. wanbestuur "misgovernment," wanluid "discordant sound"), German (wahn-), etc. Related: Wantonly; wantonness.
"one who is ill-behaved," especially (but not originally) "lascivious, lewd person," c.1400, from wanton (adj.).
1580s, from wanton (n.). Related: Wantoned; wantoning.