Bob Fry wrote:
Uh..what is AMU?

If your context is its use in the aviation newsgroups, I believe the
following definition applies:

http://www.mooneyevents.com/acronyms.html

"AMU: aviation monetary unit = $1,000 U.S. Useage: "That alternator
replacement cost me 1.5 AMUs," though it would have cost $300 for a car and
$600 for a boat. (Thanks to Kelly Vinton.)"

Prior to encountering it here, I would have answered "atomic mass unit."