dichotomus

Dichotomus is primarily a Latin adjective meaning “divided into two parts” or “twofold.” It derives from Greek dichotomos, from di- “two” and temnein “to cut.” In English, the related noun is dichotomy, and the adjective form is typically dichotomous.

In taxonomy and biology, the term is used to describe structures or patterns that split into two branches. For example, dichotomous branching refers to a growth pattern in which a branch repeatedly divides into two equal branches. Dichotomous keys, a standard tool in biology, use successive paired choices that lead to the identification of species, illustrating a dichotomous decision process.

In philosophy and logic, a dichotomy is a division of a whole into two mutually exclusive or complementary parts. The concept is also applied in medicine, psychology, and other disciplines to describe binary classifications or outcomes, such as dichotomous variables that take one of two values.

In terminology and nomenclature, dichotomus may appear as a masculine Latin epithet in scientific names to indicate a twofold feature or bifurcating habit, though in English-language usage the adjective is typically dichotomous, and the noun form is dichotomy. See also dichotomy, dichotomous key, and bifurcation.