Directly state: This is the most literal antonym.
* State
* Declare
* Assert
* Explicitly say
Contradict: These words suggest the opposite of what is implied.
* Deny
* Refute
* Contradict
Other options:
* Conceal: This implies hiding information rather than hinting at it.
* Disguise: Similar to conceal, this suggests masking the truth.
* Suppress: This implies preventing information from being communicated.
The best antonym for "imply" depends on the specific situation and what you want to convey.