unconscious vs senseless

unconscious is a noun but senseless is not a noun.

Word	Noun	Adjective	Verb	Adverb
unconscious	Yes	Yes	No	No
senseless	No	Yes	No	No

unconscious (noun)	senseless (noun)
that part of the mind wherein psychic activity takes place of which the person is unaware

unconscious (adjective)	senseless (adjective)
not conscious; lacking awareness and the capacity for sensory perception as if asleep or dead	(of especially persons) lacking sense or understanding or judgment
without conscious volition	unresponsive to stimulation
(followed by `of') not knowing or perceiving	not marked by the use of reason
	serving no useful purpose; having no excuse for being