needle in a haystack
An item that is very hard or impossible to locate, as in Looking for that screw in Dean's workshop amounts to looking for a needle in a haystack. Originating in the early 1500s, with meadow instead of haystack, this metaphor exists in many other languages as well.
Words nearby needle in a haystack
needle bath,
needle bearing,
needle biopsy,
needle exchange,
needle fly,
needle in a haystack,
needle time,
needle trades,
needle valve,
needle-holder,
needlecord