Etymology

Adjective

1. Undisciplined, unruly; not able to be controlled.
   • 1605, William Shakespeare, King Lear, IV.1:

     As Flies to wanton Boyes are we to th' Gods, / They kill vs for their sport.

2. Lewd, immoral; sexually open, unchaste.
   • 1749, Henry Fielding, Tom Jones:

     if wenches will hang out lures for fellows, it is no matter what they suffer: I detest such creatures; and it would be much better for them that their faces had been seamed with the smallpox: but I must confess I never saw any of this wanton behaviour in poor Jenny [...].

   • 1874, Thomas Hardy, Far From the Madding Crowd:

     I know I ought never to have dreamt of sending that valentine—forgive me, sir—it was a wanton thing which no woman with any self-respect should have done.

3. Playful, sportive; being merry or carefree (often used figuratively).
   • 1776, Edward Gibbon, Decline and Fall of the Roman Empire, vol. 1:

     The grave simplicity of the philosopher was ill calculated to engage her wanton levity, of to fix that unbounded passion for variety, which often discovered personal merit in the meanest of mankind.

4. Self-indulgent, fond of excess; luxurious.
   • 1776, Adam Smith, The Wealth of Nations, Book I:

     the market price will rise more or less above the natural price, according as either the greatness of the deficiency, or the wealth and wanton luxury of the competitors, happen to animate more or less the eagerness of the competition.

5. Capricious, reckless of morality, justice etc.; acting without regard for the law or the well-being of others; gratuitous.
   • 1811, Jane Austen, Sense and Sensibility:

     Edward himself, now thoroughly enlightened on her character, had no scruple in believing her capable of the utmost meanness of wanton ill-nature.

   • 2009, Ben White, The Guardian, 10 Aug 2009:

     these developments in Gaza are a consequence of the state of siege that the tiny territory has been under – a society that has been fenced-in, starved, and seen its very fabric torn apart by unemployment and wanton military destruction.

6. Extravagant, unrestrained; excessive (of speech or thought).
   • 1876, John Ruskin, Letters, 19 Jan 1876:

     But do not think it argues change of temper since I wrote the Frère review, or a wanton praise of one man and blame of another.

Synonyms

Noun

1. A pampered or coddled person.
2. An overly playful person.
3. A self-indulgent person, fond of excess.
4. A lewd or immoral person, especially a prostitute.

Verb

1. To act wantonly; become wanton.
2. To waste or squander, especially in pleasure (often with away).

   The young man wantoned away his inheritance.