der Geruch
smell
The perception taken in through the nose from scents in the air; a fragrance or stench.
Ich liebe den Geruch von frisch gemähtem Gras im Sommer.
I love the smell of freshly cut grass in summer.

smell
Loading your saved state.
smell
The perception taken in through the nose from scents in the air; a fragrance or stench.
Ich liebe den Geruch von frisch gemähtem Gras im Sommer.
I love the smell of freshly cut grass in summer.

'Der Geruch' (the smell) is the noun derived from the verb 'riechen' (to smell). This connection helps you understand the meaning: 'riechen' is the action, and 'der Geruch' is what one perceives.
Ich rieche einen seltsamen Geruch in der Küche.
I smell a strange odor in the kitchen.
'Geruch' (smell) itself is neutral. Whether the smell is good or bad is determined by an adjective, e.g. 'ein guter/angenehmer Geruch' (a good/pleasant smell) or 'ein schlechter/unangenehmer Geruch' (a bad/unpleasant smell).
Der angenehme Geruch von Lavendel beruhigt mich.
The pleasant smell of lavender calms me.
To describe what something smells like, German uses the preposition 'von' followed by the dative. The structure is: 'der Geruch von etwas' (the smell of something).
Ich mag den Geruch von frisch gebackenem Brot.
I like the smell of freshly baked bread.
The idiom 'im Geruch stehen, etwas zu tun' means that someone has a bad reputation or is suspected of having done something negative. The expression always has a negative connotation.
Der Politiker steht im Geruch der Korruption.
The politician is suspected of corruption.
reputation / call
'der Ruf' and 'der Geruch' are usually very different: 'Ruf' means the reputation of a person or thing, while 'Geruch' usually means something you perceive with your nose. There is an overlap in the fixed expression 'im Geruch stehen'. In that case, 'Geruch' does not really mean a smell, but a suspicion or reputation, often negative. Learners may confuse this because 'Geruch' is used figuratively in this expression. For general reputation, 'Ruf' is the normal word; 'im Geruch stehen' is used only as a fixed expression.

Der Verkäufer steht im Geruch, alte Geräte als neu zu verkaufen.
The seller is suspected of selling old devices as new.
Die kleine Bäckerei hat in der ganzen Stadt einen guten Ruf.
The small bakery has a good reputation throughout the city.