needle-in-a-haystack

listen to the pronunciation of needle-in-a-haystack
الإنجليزية - التركية
samanlıkta iğne
الإنجليزية - الإنجليزية
Alternative spelling of needle in a haystack
Something that is difficult or impossible to locate; something impossibly complex or intractable

You'll never find the paper you need on her desk. You're looking for a needle in a haystack.

something which is nearly impossible to do or find (part of the adage: "it's like looking for a needle in a haystack")