flakey

(adjective) unreliable

Example Sentences:

The students thought their new professor was flakey because he always started class 10 minutes late and ended class 10 minutes early.

A: Are you having fun with your new boyfriend?
B: Sometimes. He’s kind of flakey. He always cancels our plans at the last minute.

My mom asked Hailey to pick her up from the airport, because she said I would probably be late because I’m so flakey.

From the Blogs:

Anti-War Obamabots Flakey Position

Media:

Similar idioms:

1. flake
2. clamp down on something
3. have a bone to pick with someone
4. better late than never
5. epic fail