haystack

1. (canoeing) A standing wave in a rapid.

2. (programming) The text string within which another string is searched for. (see: needle in a haystack)Examples: "Both of these functions will look through the haystack for the specified needle and, if they find it, will return the portion of the string from the beginning of the needle to the end of the haystack."

3. (more generally) Any place or collection of items through which one searches for something that is rare and hard to find.Examples: "But the point of confining the Kansas City gun experiment to the worst parts of the worst neighborhoods was to make the haystack just a little smaller, and to make the inevitable trade-off between fighting crime and harassing innocent people just a little more manageable."broadly