1. verb, slang To suddenly express anger or excitement in a very visible way. Mom will freak when she finds out we broke her vase! I totally freaked when I heard we'd won tickets to the concert.

2. verb, slang To be startled or frightened. I completely freaked at the sight of that huge needle.

3. noun, slang A person or thing considered highly irregular, unconventional, or bizarre. Can be derogatory when used to describe a person. In this city, you can be a freak and not worry about people staring at you all the time. Look at that freak! Have you ever seen a bug like that? Dude, you need to stop hanging out with the freaks. What a bunch of weirdos.

4. noun, slang A person who is very sexually uninhibited. I've heard she's a real freak in bed.

5. An interjection used as a more mild version of "fuck." Freak! Where did I put my keys?