What do you know for sure?

What do you know (for sure)?

Used as an informal, familiar greeting. Hello, Tom—what do you know for sure? A: "Hey, Mike. B: "Bill! Long time no see. What do you know?"
See also: know, what
Farlex Dictionary of Idioms.

What do you know for sure?

Inf. How are you?; What do you know? (Familiar. An elaboration of What do you know? Does not require a direct answer.) Tom: Hey, man! What do you know for sure? Bill: Howdy, Tom. What's new? John: How are you doing, old buddy? Bill: Great, John! John: What do you know for sure? Bill: Nothing much.
See also: know, what
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.
See also:
  • know what
  • as we know it
  • by any chance
  • I know
  • AFAIK
  • before you know where you are
  • in the biblical sense
  • closed book, a
  • a closed book
  • before you know it