motiveless vs wanton

motiveless is not a noun while wanton is a noun.

Word	Noun	Adjective	Verb	Adverb
motiveless	No	Yes	No	No
wanton	Yes	Yes	Yes	No

As adjectives, motiveless and wanton are synonyms defined as:

Other synonyms of motiveless include unprovoked.

motiveless (noun)	wanton (noun)
	lewd or lascivious woman

motiveless (adjective)	wanton (adjective)
occurring without motivation or provocation	casual and unrestrained in sexual behavior
	occurring without motivation or provocation

motiveless (verb)	wanton (verb)
	behave extremely cruelly and brutally
	engage in amorous play
	become extravagant; indulge (oneself) luxuriously
	spend wastefully
	waste time; spend one's time idly or inefficiently
	indulge in a carefree or voluptuous way of life