[adj] requiring little mental effort; "mindless tasks"
[adj] lacking the thinking capacity characteristic of a conscious being; "the shrieking of the mindless wind"
[adj] not marked by the use of reason; "mindless violence"; "reasonless hostility"; "a senseless act"
[adj] not mindful or attentive; "while thus unmindful of his steps he stumbled"- G.B.Shaw
[adj] complacently or inanely foolish
amnesiac, amnesic, asinine, fatuous, foolish, forgetful, inane, meaningless, nonintellectual, reasonless, senseless, unmindful, unreasonable, vacuous