Word Origin & History
shag1592, "cloth having a velvet nap on one side," from O.E. sceacga "rough matted hair or wool," cognate with O.N. skegg "beard," from P.Gmc. *skagjan, perhaps related to O.H.G. scahho "promontory," with a connecting sense of "jutting out, projecting." Of tobacco, "cut in fine shreds," it is recorded from
1789; of carpets, rugs, etc., from 1946. Shagbark as a type of hickory is from 1751. Shaggy is attested from c.1590 (earlier shagged, O.E.); shaggy-dog story first recorded 1945.
shag"copulate with," 1788, probably from obs. verb shag (c.1380) "to shake, waggle," which probably is connected to
shake (cf. shake, shake it in U.S. blues slang from 1920s, ostensibly with ref. to dancing).
"And þe boot, amydde þe water, was shaggid." [Wyclif]
Also the name of a dance popular in U.S. 1930s and '40s. The baseball verb meaning "to catch" (fly balls) is attested from 1913, of uncertain origin or connection to other senses of the word.