A wild goose chase is a long hopeless search for something you will never find. Send him on a wild goose chase, a complete wild goose chase.
The waste of effort is the point, and the person is usually sent on one by somebody else. The phrase is in Shakespeare, where it named a kind of horse race rather than a hunt.
1phrasewild goose chaseA long hopeless search for something you will never find.
“The whole afternoon turned into a wild goose chase across three offices.”
wild goose chase is a phrase.
wild-goose chase Early recorded use refers to a type of 16th century horse race where everyone had to try to follow the erratic course of the lead horse, like wild geese have to follow their leader in formation. Mentioned in 1593 in the English poet Gervase Markham’s book about horsemanship. Also mentioned in the William Shakespeare play Romeo and Juliet, Act 2, scene 4 by the character Mercutio: “Nay, if our wits run the wild-goose chase, I am done; for thou hast more of the wild goose in one of thy wits than, I am sure, I have in my whole five.” Mentioned in Robert Burton, Anatomy of Melancholy (1621). Common use in the current may be the origin for the sport sense.
Etymology from Wiktionary, CC BY-SA
Practised in Idioms