from
The Collaborative International Dictionary of English v.0.48
golden snitch \gold"en snitch`\ (g[=o]ld"'n sn[i^]ch), n. [ca.
2000]
1. A fictional object shaped like a small golden sphere with
wings, described in the series of "Harry Potter" novels by
J.K. Rowling. It is used in a fictional game called
Quidditch, in which wizards on broomsticks fly through the
air and, among other things, try to catch the golden
snitch, which flies quickly and erratically, and is
therefore difficult to catch.
[PJC]
2. Hence: [metaphorically] Some object that is difficult to
catch, or a goal that is difficult to achieve.
[PJC]