When "for" means "because of":
* Against: "He argued against the new policy."
* Despite: "She went to the party despite her cold."
* In spite of: "He finished the marathon in spite of his injury."
When "for" means "in support of":
* Against: "She voted against the proposal."
* Opposed to: "They were opposed to the new law."
* Contrary to: "This evidence is contrary to his claims."
When "for" means "intended for":
* From: "This gift is from my friend."
* By: "This book was written by a famous author."
* Of: "The cat is of the tabby breed."
When "for" means "during":
* Before: "They met before the party."
* After: "He called his mother after the meeting."
It's important to understand the specific meaning of "for" in your context to choose the most accurate antonym.