pipe-dream

verb (used without object), pipe-dreamed or pipe-dreamt, pipe-dream·ing.

1. to indulge in pipe dreams; fantasize.

noun

1. any fantastic notion, hope, or story: Her plans for a movie career are just a pipe dream.

noun

1. a fanciful or impossible plan or hope

n.1870; the sort of improbable fantasy one has while smoking opium; from pipe (n.1) + dream (n.). Old English pipdream meant “piping.” A fantastic notion or vain hope, as in I’d love to have one home in the mountains and another at the seashore, but that’s just a pipe dream. Alluding to the fantasies induced by smoking an opium pipe, this term has been used more loosely since the late 1800s.