geek out

verb4

1. •
   (slang) To enthuse about a specific topic; to be engrossed in an interest, especially in discussing it with others.

   • Sorry, I didn't mean to spend fifteen minutes discussing the definition of "decimate". I guess I geeked out for a bit.
2. •
   (slang) To do geeky things; to act geeky.

   • Hey guys, let's geek out tonight and have a code-a-thon!
3. •
   (slang) To be scared, freak out, panic; to hesitate in fear.

   • I geeked out there for a minute and broke the lockpick.
4. •
   (slang) To scare or freak out (somebody).