If you're talking about personality:
* Antipatica: This is the most direct opposite, meaning "unpleasant" or "unlikeable."
* Desagradable: This means "unpleasant" or "disagreeable," suggesting someone is not enjoyable to be around.
* Grosera: This means "rude" or "impolite," emphasizing a lack of good manners.
* Maleducada: This means "ill-mannered" or "uneducated," implying someone lacks proper social skills.
If you're talking about physical appearance:
* Fea: This means "ugly" or "unattractive," and is considered a harsh term.
* Poco atractiva: This means "not attractive," and is a more polite way to say someone is not physically appealing.
If you're talking about a situation or event:
* Desagradable: This means "unpleasant" or "disagreeable," suggesting something is not enjoyable.
* Incomoda: This means "uncomfortable" or "awkward," suggesting something is making someone feel uneasy.
Remember that the best word to use will depend on the specific situation and the nuance you want to convey.