phenotype āļāļ·āļāļāļ°āđāļĢ phenotype āļāļ·āļāļāļ°āđāļĢ The observable physical or biochemical characteristics of an organism, as determined by both genetic makeup and environmental influences.The expression of a specific trait, such as stature or blood type, based on genetic and environmental influences.An individual or group of organisms exhibiting a particular phenotype.