Direct Opposites:
* Neglect: This implies a complete disregard or lack of use.
* Waste: This suggests using something in a way that doesn't produce value.
* Disregard: This implies ignoring or not considering something.
Opposite in Function:
* Abandon: This suggests giving up on using something.
* Discard: This implies getting rid of something completely.
* Ignore: This means paying no attention to something.
Other Possibilities:
* Avoid: This means deliberately not using something.
* Reject: This implies refusing to use something.
* Forgo: This means choosing not to use something.
The best antonym for "utilize" will depend on the specific context and the intended meaning.