irrational
1. [ adjective ] not consistent with or using reason
Examples:

"irrational fears" "irrational animals"

Related terms: rational blind superstitious incoherent reasonless nonrational jaundiced incoherent unreasonable illogical
2. [ adjective ] (math) real but not expressible as the quotient of two integers
Examples:

"irrational numbers"

Related terms: rational mathematics ratio
Similar spelling:   irrationally
  irrationality