sling (n.1) Look up sling at Dictionary.com
c.1300, "implement for throwing stones," from an unidentified continental Germanic source (such as Middle Low German slinge "a sling"); see sling (v.). The notion probably is of a sling being twisted and twirled before it is thrown. Sense of "loop for lifting or carrying heavy objects" first recorded early 14c. Meaning "piece of cloth tied around the neck to support an injured arm" is first attested 1720.
sling (v.) Look up sling at Dictionary.com
c.1200, "to knock down" using a sling, later "to throw" (mid-13c.), especially with a sling, from Old Norse slyngva, from Proto-Germanic *slingwanan (cognates: Old High German slingan, German schlingen "to swing to and fro, wind, twist;" Old English slingan "to creep, twist;" Old Frisian slinge, Middle Dutch slinge, Old High German slinga, German Schlinge "sling;" Middle Swedish slonga "noose, knot, snare"), from PIE *slengwh "to slide, make slide; sling, throw." Meaning "to hang from one point to another" (as a hammock) is from 1690s. Related: Slung; slinging.
sling (n.2) Look up sling at Dictionary.com
sweetened, flavored liquor drink, 1807, American English, of unknown origin; perhaps literally "to throw back" a drink (see sling (v.)), or from German schlingen "to swallow."
sling (n.3) Look up sling at Dictionary.com
"act of throwing," 1520s, from sling (v.).