amino acid
Word family nounamino acidamine
a·mi·no ac·id /əˌmiːnəʊ ˈæsəd, əˌmaɪ- $ -noʊ-/ noun [countableC] amino acid• Tryptophan is a naturally occurring amino acid. Origin amino acid (1800-1900) amine type of chemical compound ((19-21 centuries)), from ammonia