General Antonyms:
* Loss: This is the most general antonym, meaning the opposite of getting something back.
* Abandonment: This implies leaving something behind and not retrieving it.
* Disappearance: This suggests something is lost or gone, and retrieval is impossible.
Specific Antonyms:
* Disposal: This implies getting rid of something permanently, the opposite of keeping it or retrieving it.
* Destruction: This means something is broken or destroyed, making retrieval impossible.
* Concealment: This implies hiding something, making it difficult to retrieve.
Other Possibilities:
* Retention: This suggests keeping something and not returning it, the opposite of retrieval.
* Detainment: This suggests holding something back and not releasing it, the opposite of retrieving it.
The best antonym will depend on the specific situation and what you are trying to express.