*Can A Word Be Its Own Opposite?*

Yes! They are called *Contronyms*—words that are their own antonyms, depending on usage.
Here are a few examples

*Dust* :
can mean ‘to add fine particles’ or ‘to remove fine particles.

*Left* :
can mean both
‘remaining’ and ‘departed’.

*Off* :
can mean both ‘activated’ and ‘deactivated’.
Eg:- “Set off” - Activated
“ Switch off - Deactivated

*Oversight* :
means both ‘watchful care’ and ‘an inadvertent error’.

*Screen* :
can mean both ‘to show’ and ‘to hide’.

*Sanction*
can mean both ‘a penalty for disobeying a law’ and ‘official permission or approval for an action.