Example : Mindless violence.
Reasonless hostility.
A senseless act.

Synonyms : mindless, reasonless

Example : He lay insensible where he had fallen.
Drugged and senseless.

Synonyms : insensible, out of it

Example : Otiose lines in a play.
Advice is wasted words.
A pointless remark.
A life essentially purposeless.
Senseless violence.

Synonyms : otiose, pointless, purposeless, superfluous, wasted

Synonyms : nitwitted, soft-witted, witless