1. A dreamlike, romantic, or uncritical sense of well-being.
2. A cluster of stars too distant to be seen individually, resembling a dimly luminous cloud of dust. Not in scientific use.
3. Minute particles of matter that fall to Earth from the stars. Not in scientific use.

have stardust in (one's) eyes

1. To be uncritically or unrealistically optimistic.

The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.