General Antonyms:
* Heedless: This is the most direct antonym, meaning paying no attention or disregarding something.
* Inattentive: Means not paying attention, lacking focus, or being oblivious.
* Careless: Indicates a lack of concern or attention to detail.
* Neglectful: Implies a deliberate disregard or failure to take care of something.
More Specific Antonyms (Depending on Context):
* Disregardful: This emphasizes the act of deliberately ignoring something.
* Indifferent: Suggests a lack of interest or concern.
* Oblivious: Means completely unaware of something.
The best antonym for "heedful" will depend on the specific situation and the nuances of the sentence.