Source : Webster's Revised Unabridged Dictionary (1913)

Irrelative \Ir*rel"a*tive\, a.
   Not relative; without mutual relations; unconnected. --
   {Ir*rel"a*tive*ly}, adv.

   {Irrelative chords} (Mus.), those having no common tone.

   {Irrelative repetition} (Biol.), the multiplication of parts
      that serve for a common purpose, but have no mutual
      dependence or connection. --Owen.