What is the word Opposite of fragrance?

There isn't a single perfect opposite for "fragrance" because it depends on what aspect of fragrance you want to oppose. Here are some possibilities:

Depending on the context:

* Odor: This refers to any smell, good or bad.

* Stench: This specifically refers to a strong, unpleasant smell.

* Foulness: This refers to something that is extremely unpleasant to the senses.

* Smelllessness: This refers to the complete lack of any scent.

* Reek: This refers to a strong, offensive smell.

Depending on the intention:

* Aversion: This refers to a strong dislike of a smell.

* Repulsion: This refers to a feeling of disgust towards a smell.

The best word to use will depend on the specific context and the meaning you want to convey.