When it comes to antonyms for the phrase "smelling out," there are several options. One antonym could be "ignoring," as it represents the opposite of sniffing out a scent to detect or track something down. Another antonym could be "overlooking," as it also suggests a lack of attention or disregard for a scent or something that may be hidden. "Disregarding," "neglecting," and "missing" are also possible antonyms for "smelling out," as they all imply a failure to detect or perceive a scent, clue or sign. Overall, there are many antonyms to "smelling out" that represent a lack of thoroughness, attention, and awareness.