The phrase "take air into one's nostrils" is most commonly referred to as "smelling." However, there are several synonyms that can be used to express the same action. "Detecting an odor" or "perceiving a fragrance" are a couple of alternatives for smelling. You can also use "inhaling a scent" or "sniffing" to describe the same action. Other synonyms for smelling include "snuffing," "whiffing" and "scenting". Regardless of the choice of words, the concept remains the same; taking air into one's nostrils to perceive a scent or odor.
