The difference between Merciless and Wanton

When used as adjectives, merciless means showing no mercy, whereas wanton means undisciplined, unruly.

Wanton is also noun with the meaning: a pampered or coddled person.

Wanton is also verb with the meaning: to rove and ramble without restraint, rule, or limit.

check bellow for the other definitions of Merciless and Wanton

Wanton as an adjective (archaic):

Undisciplined, unruly; not able to be controlled.
Wanton as an adjective (obsolete):

Playful, sportive; merry or carefree.
Wanton as an adjective:

Lewd, immoral; sexually open, unchaste.
Wanton as an adjective:

Capricious, reckless of morality, justice etc.; acting without regard for the law or the well-being of others; gratuitous.
Wanton as an adjective (archaic):

Extravagant, unrestrained, excessive.

Wanton as a noun:

A pampered or coddled person.
Wanton as a noun:

An overly playful person; a trifler.
Wanton as a noun:

A self-indulgent person, fond of excess.
Wanton as a noun (archaic):

A lewd or immoral person, especially a prostitute.

Wanton as a verb (intransitive):

To rove and ramble without restraint, rule, or limit; to revel; to play loosely; to frolic.
Wanton as a verb (transitive):

To waste or squander, especially in pleasure (most often with away).

Examples:

"The young man wantoned away his inheritance."
Wanton as a verb (intransitive):

To act wantonly; to be lewd or lascivious.