- not essential; of relatively no importance; unnecessary
- Biochem. designating biological compounds, esp. amino acids, required by living systems, that can be made in adequate amounts from other dietary constituents
- Having little or no importance; not essential.
- Being a substance that is required for normal functioning but does not need to be included in the diet because of the body's ability to synthesize it from other nutrients: nonessential amino acid.
nonessential - Medical Definition