What does the DNA sequence being 'degenerate' mean?

Amino acids are coded for by specific codons. There are some instances where some particular amino acids can be coded for by more than one codon (codon being three nucleotides bonded together). This is known as DNA being dengerate. If we take Valine (val) as an example, it is coded for by the codons GUU, GUC, GUA, GUG. This means that if the third nucleotide base is substituted by Adenine, Guanine, Cytosine or Uracil, it will still code for Valine, reducing the likelihood of genetic mutations that may prove to be harmful for that individual!