Olfaction is the sense of smell, and there are several synonyms for this word. One synonym is "olfactition," which is the act of perceiving smells. Another synonym is "smell," which is a simple one-word term for detecting odors. Another term is "odor perception," which refers to detecting smells in the air. Other synonyms include "nasal sensation," "olfactory sensation," and "scent detection." Some people may also use phrases like "scent recognition" or "aroma detection" to refer to the sense of smell. Overall, there are many ways to describe olfaction, and using synonyms can make it easier to communicate about this sense in different contexts.