off the top of one's head
- Used other than with a figurative or idiomatic meaning: see off, top, head.
- (idiomatic) In an extemporaneous manner; without careful thought, preparation, or investigation.
- I cannot think of any good examples off the top of my head, but give me a couple of hours and I'm sure I could come up with something.
- Usually used to characterize the manner of one's thinking or speaking.
- Often indicates a random piece of information put forth by a knowledgeable expert in the topic spoken within.
in an extemporaneous manner; without careful thought, preparation, or investigation