Sustituto

Sustituto is a Spanish noun that refers to a person or thing that replaces another, either temporarily or as an alternative. The term can indicate someone who steps into a role in the absence of the titular person, or more generally anything that serves as a replacement or surrogate for something else. It is used across different domains to denote an alternative that performs the same function.

In education, a substitute teacher is called a profesor sustituto, who teaches while the regular teacher is unavailable. In administration and politics, a cargo sustituto designates a position temporarily filled by another person. In medicine, the phrase tratamiento sustitutivo or terapia de sustitución describes therapies that replace a deficient biological process. In economics, bienes sustitutos are goods that can replace each other to satisfy the same need.

In science, particularly in chemistry, a sustituto refers to a group that replaces another group in a molecule; the common term is grupo sustituyente. This concept also appears in biology and pharmacology to indicate replacements or alternatives within systems and treatments.

Etymology and usage notes: sustitut o derives from Latin substitūtus. In Spanish, the feminine form sustituta and the plural sustitutos are used. Regional variation influences connotations; in some contexts more specific expressions such as sustituto temporal or sustitución are preferred depending on the field.

See also: sustitución, sustituyente, bien sustituto, sustituto químico.