non·sen·si·cal
adj.
1.Lacking intelligible meaning: a nonsensical jumble of words.
2.Foolish; absurd: nonsensical ideas.
ir·ra·tion·al
adj.
1. a.Not endowed with reason.
b.Affected by loss of usual or normal mental clarity; incoherent, as from shock.
c.Marked by a lack of accord with reason or sound judgment: an irrational dislike.