Sthnoof is the condition of being unable to sniff or smell due to extreme nasal congestion and stuffiness. When one cannot see, they are blind. When one cannot hear, they are deaf. When one cannot speak, they are mute. When one cannot smell, they are sthnoof.
Son: "BOB! Cad I stay home frob school?"
Mom: "What's wrong?"
Son: "I'b dot feeling very good. By head and by throat hurts and I'b coughing and I can't sbell adythig."
Mom: "Are you sthnoof?"
Son: "Baybe a little."