Degeneracy is basically things that are different structurally but create the same results. Some codons (3 nucleotides that code for an amino acid during translation) may code for the same amino acid. Let's use the example argenine. Multiple codons can code for that specific amino acid but for polypeptides, changing those specific codons may give the same result. For example, say argenine was coded with CGU and was changed to CGC. Both these results may still produce the amino acid argenine, meaning polypeptide didn't change, but the genetic code did change.
I'm not sure if that's the answer you were expecting, but yeah.