General opposites:
* Rare: This is the most straightforward opposite, meaning something that is found infrequently or in limited places.
* Scarce: Similar to rare, this implies a limited supply or availability.
* Uncommon: Something that is not frequently encountered or seen.
* Exceptional: This suggests something that is unusual or stands out from the norm.
Specific to context:
* Limited: If ubiquitous refers to widespread presence, the opposite could be limited to a specific area or group.
* Local: If ubiquitous means something is found everywhere, the opposite could be something that is specific to a particular place.
* Nonexistent: This is the most extreme opposite, indicating something that does not exist at all.
The best opposite word depends on the specific meaning of "ubiquitous" in the sentence you are considering.