Abstract: The development of new molecular approaches in biology and biotechnology introduced new scientific terms which include genome, genomics, methylome and methylomics. These are currently used in the literature of molecular and synthetic biology to refer various molecular concepts and applications. The present study is about the requirement of new “ome” and “omics” terms. This is because there are unique structural and functional aspects associated with genome and methylome at specific regions in the DNA sequence which are not explained by the two currently used terms methylome and genome. There is a requirement for new ome/omics terms to refer specific structural and functional matters associated with particular specialized zones in the DNA sequences. These genomic regions contain both the fifth base “methyl cytosine” and the other four coding bases. Methylated and non methylated DNA sequences are involved in gene expression of RNA and proteins, beside their role in the structural organization of the DNA sequence and the chromosome. In this study I suggest introducing two words which are derived from the established scientific terms “genome, genomics, methylome and methylomics”. The two new derived words are: gethylome and gethylomics. I suggest that these two words might be useful and could be used to explain various issues related to specific regions in the DNA sequence and chromosomes of eukaryotic organisms which contain the fifth base. Furthermore, gethylomics will help to refer more precisely to new applications in synthetic biology and genomics to design or redesign specific gethylomic circuits.