destitute or deprived of sensation; unconscious.

lacking mental perception, appreciation, or comprehension.

stupid or foolish, as persons or actions.

nonsensical or meaningless, as words

This letter is either cryptic or senseless.

adjective

feeling , intelligent , rational , reasonable , sensible , wise

adjective

absurd , asinine , batty , crazy , daft , doublespeak , double talk , fatuous , flaky , foolish , idiotic , illogical , imbecilic , inane , incongruous , inconsistent , insignificant , irrational , ludicrous , mad , mindless , moronic , nonsensical , nutty , pointless , purportless , purposeless , ridiculous , simple , stupid , trivial , unimportant , unintelligent , unmeaning , unreasonable , unsound , unwise , wacky * , without rhyme or reason , meaningless , brainless , insensate , silly , weak-minded , witless , cold , insensible , comatose , deadened , dumb , inept , numb , oblivious , unconscious , unfeeling