Source : Webster's Revised Unabridged Dictionary (1913)

Insignificant \In`sig*nif"i*cant\, a.
   1. Not significant; void of signification, sense, or import;
      meaningless; as, insignificant words.

   2. Having no weight or effect; answering no purpose;
      unimportant; valueless; futile.

            Laws must be insignificant without the sanction of
            rewards and punishments.              --Bp. Wilkins.

   3. Without weight of character or social standing; mean;
      contemptible; as, an insignificant person.

   Syn: Unimportant; immaterial; inconsiderable; small;
        inferior; trivial; mean; contemptible.

Source : WordNet®

insignificant
     adj 1: not large enough to consider or notice [syn: {trivial}]
     2: not worthy of notice [syn: {undistinguished}]
     3: signifying nothing; "insignificant sounds"; "his
        response...is picayune and unmeaning"- R.B. Pearsall [syn:
         {unmeaning}]
     4: of little importance or influence or power; of minor status;
        "a minor, insignificant bureaucrat"; "peanut politicians"
        [syn: {peanut}]
     5: not important or noteworthy [syn: {unimportant}] [ant: {significant}]