General term for smell, covering both pleasant and unpleasant odors. The kanji 臭い is used specifically for bad smells.
台所からいい匂いがする。
A nice smell is coming from the kitchen.
この部屋は変な臭いがする。
This room smells strange.
Metaphorical use for the atmosphere, mood, or impression given off by a person, place, or thing. Often used with 感じ or 雰囲気.
彼には都会の匂いがする。
He has an urban air about him.
この町には歴史の匂いが感じられる。
You can feel the aura of history in this town.
faint pattern along a sword's temper line
Specialized term in Japanese sword appreciation; refers to a mist-like visual effect along the hamon (temper line). Rare outside this domain.
日本刀の鑑賞では、刃文に現れる匂いも重要な要素だ。
In appreciating Japanese swords, the faint pattern appearing along the temper line is also an important element.
I smelled the flower.
I sensed something suspicious about his story.
The smell of coffee is drifting through the room.
This fish has a strong smell.
I got rid of the smell in the room with a deodorizer.
臭い is the plain, everyday word for a smell (good or bad depending on context), while 臭気 is a stiffer term specifically for a bad odor.
匂い is a neutral, everyday word for any smell, pleasant or not, whereas 香気 refers specifically to an elegant, pleasant fragrance.
匂い is a neutral, everyday word for smell that can be good or bad, while 薫 specifically denotes a pleasant, refined aroma.
be fragrant; give off a strong scent; be enveloped in a smell · be radiant; be attractive; exude charm
fragrant iris; sweet flag; orris