"unkempt; having rough, coarse, long hair," 1580s, from shag (n.) + -y (2). Related: Shaggily; shagginess. Earlier was shagged, from Old English sceacgede "hairy;" compare Old Norse skeggjaðr, Danish skægget "bearded." The shaggy-dog story as a type of absurd joke built into a long, tedious story, is attested from 1943 and was a fad in the mid-40s. The origin of the phrase may be in vaudeville; the most-often cited original example involves an Englishman who offers a reward for a lost shaggy dog, an enterprising American who, with great difficulty, tracks him down and offers a shaggy dog that he claims is the one, and his curt reception: "Not that shaggy." But the story does not seem to be older than the phrase.
updated on July 24, 2022