Setiferous is an unusual word that refers to an object or organism bearing bristles, setae, or hairs. Antonyms for setiferous could include smooth, hairless, bald, sleek, and glabrous. These words describe surfaces or organisms that lack the hairy or bristly texture associated with setiferous. Smooth surfaces are notably without bumps, roughness, or hairlike projections, while baldness refers to a lack of hair on an organism's scalp or other body parts. Sleek and glabrous imply surfaces that are free of hair and are often characterized by their smooth and shiny appearance. Overall, these antonyms illustrate the opposite of the setiferous attribute, instead highlighting attributes of smoothness, hairlessness, and slickness.