S: (adj) meaningless, nonmeaningful (having no meaning or direction or purpose) "a meaningless endeavor"; "a meaningless life"; "a verbose but meaningless explanation"
W: (adj) meaningful [Indirect via meaningless] (having a meaning or purpose) "a meaningful explanation"; "a meaningful discussion"; "a meaningful pause"
S: (adj) mindless (requiring little mental effort) "mindless tasks"
S: (adj) unmindful, forgetful, mindless (not mindful or attentive) "while thus unmindful of his steps he stumbled"- G.B.Shaw
S: (adj) mindless, vacuous (devoid of intelligence or thought) "a vacuous mind"; "a vacant expression"
S: (adj) mindless, reasonless, senseless (not marked by the use of reason) "mindless violence"; "reasonless hostility"; "a senseless act"