General words:
* Scent: A pleasant smell
* Odor: A smell, often used for unpleasant smells
* Aroma: A strong, pleasant smell, often associated with food or flowers
* Fragrance: A delicate, pleasant smell, often used for perfumes
* Reek: A strong, unpleasant smell
* Stench: A very strong, foul smell
* Fume: A strong, often unpleasant smell, especially from smoke or gas
Words related to the act of smelling:
* Inhale: To breathe in
* Sniff: To smell something quickly or briefly
* Snuff: To smell something closely, often with the nose
* Whiff: A brief, light smell
* Waft: To move gently through the air, as with a smell
Words related to the quality of a smell:
* Musty: Having a stale, damp smell
* Aromatic: Having a strong, pleasant smell
* Putrid: Having a foul, rotten smell
* Rancid: Having a spoiled, fatty smell
* Pungent: Having a strong, sharp smell
The best word to use depends on the specific situation.