Direct Opposites:
* Unclassify: This directly reverses the action of classifying, meaning to remove something from a category.
* Declassify: This is often used specifically for removing confidential information from classification.
* Disclassify: This is a less common but similar term to declassify.
Other Opposites:
* Group: This implies bringing together items without necessarily assigning them to a specific category.
* Combine: This is similar to group, but it can also imply merging different items into a single entity.
* Individualize: This focuses on treating items as unique and distinct, rather than grouping them together.
* Randomize: This means to distribute items without any specific order or classification.
Example:
* Classify: "The librarian classified the books by genre."
* Unclassify: "The librarian unclassified the books after the new cataloging system was implemented."
The best opposite of "classify" will depend on the specific situation and the intended meaning.