General Antonyms:
* Boring: This is the most common and direct opposite of "interesting."
* Dull: Similar to boring, but implies a lack of excitement or stimulation.
* Tedious: This suggests something that is tiresome and monotonous.
* Monotonous: This refers to something lacking in variety and excitement.
More Specific Antonyms:
* Unremarkable: This implies something that is not noteworthy or exceptional.
* Ordinary: This suggests something that is common and typical.
* Bland: This describes something that lacks flavor or character.
* Uninspiring: This refers to something that doesn't motivate or excite.
The best antonym will depend on the specific meaning of "interesting" in the context. For example, if you are talking about an interesting book, "unremarkable" or "ordinary" might be better antonyms than "boring."