Endophenotype refers to a specific trait or measurable biological marker that is associated with a certain disorder or condition. There are several synonyms for endophenotype, such as biomarker, intermediate phenotype, and quantitative trait. A biomarker is a measurable substance or characteristic that indicates the presence or severity of a disease or condition. An intermediate phenotype is a biological trait that is not directly related to the disorder itself but can provide insight into its underlying mechanisms. A quantitative trait is a characteristic or behavior that can be measured and analyzed statistically. These synonyms are often used interchangeably with endophenotype in scientific literature and research.