traseiro

Traseiro is a Portuguese adjective and noun meaning "rear," "back" or "hind." As an adjective it describes the position of something toward the back (for example, banco traseiro for back seat or roda traseira for rear wheel). As a noun it is commonly used in everyday speech to refer to the buttocks or the posterior part of an object or animal.

Usage spans everyday language, technical contexts and anatomy. In automotive and mechanical language, traseiro appears in compound terms such as eixo traseiro (rear axle), farol traseiro (rear light) and suspensão traseira (rear suspension). In anatomical or colloquial contexts, traseiro can denote the buttocks or the rear portion of the body, sometimes used interchangeably with posterior or nádegas depending on register and formality.

Etymology traces to the Portuguese word trás ("behind") combined with the adjectival/relational suffix -eiro, forming a word that denotes position relative to the back. The term has close cognates in other Romance languages (for example Spanish trasero) with similar meanings.

Register and connotation vary by context: technical and descriptive uses are neutral, while referential use for body parts may be considered informal or mildly coarse depending on the audience. Common phrases include lugar traseiro (rear place), posição traseira (rear position) and parte traseira (rear part).