Meaning of frameshift

frame•shift

Pronunciation: (frām'shift"), [key]
— n. Genetics.
  1. the addition or deletion of one or more nucleotides in a strand of DNA, which shifts the codon triplets of the genetic code of messenger RNA and causes a misreading during translation, resulting in an aberrant protein and therefore a mutation.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.