The word "sniffier" is an adjective that refers to someone who is arrogant, haughty or disdainful. In contrast, there are several antonyms (opposites) for this word that describe people with down-to-earth, humble or modest personalities.
One antonym for "sniffier" is "unpretentious", which means that someone is honest and authentic in their character without any desire to impress others. Another antonym is "approachable", which describes someone who is easy to talk to and friendly, unlike someone who is sniffy and distant.
Additionally, the term "unassuming" can be used as another antonym for "sniffier", as it describes a person who is modest and humble, rather than arrogant and conceited.