’A sling’ is a catapult-like device used for throwing projectiles. Simply, a circular piece of cloth that can be used to throw rocks.
- ‘I used a sling-shot to throw the rock into the air, and killed a bird’.
So ‘to sling’ implies - to throw something in a wide and circular arc - the kind of trajectory you’d get if you picked up a stone in a hoop of cloth and used the cloth to fling the stone into the air. The sling extends the length of your arm, and works as a lever to make your circular throw (circular of course, because your arm is attached at your shoulder) more powerful and over a longer distance.
Hence ‘to sling’ something out, or ‘sling it away’ usually means ‘to throw with force’. To ‘sling out’ implies ‘to throw away’ (rubbish).
Note: Another word for sling, or sling shot, is catapult. A slightly different but related device to ‘a sling’ - it can also be used as a similar-meaning verb ie ‘to catapult’ - ‘to throw with force’.
‘Eject’ means ‘to exit something from where it is now’.
‘Launch’ means ‘to deliberately push forward and let go of’ - to push something up into the air’ (or, into water etc).
‘The USA launched a new space shuttle into the air’.
‘The sailboat was launched at the jetty’.
‘The PR girl launched the new product online’ (she ‘pushed it forward’ - towards its audience).
‘The rock star launched himself into the audience, caught by the many hands of his fans’. (He ‘launched himself’ - into the audience).
Looking at the etymology will often give a truer sense of the word than online opinion - as the etymology encapsulates the original intention behind the word:
‘To hurl a missile, discharge with force’
You’ll clearly see it means ‘to throw - out’
You’ll see it’s original meaning is ‘Noose or snare’ - that’s another traditional use for the same ‘circular piece of fabric’ or ‘sling’ - a sling (or ‘noose’) was used for catching animals as well as for throwing stones. The same circular shaped piece of fabric also supports a broken arm and is still called ‘a sling’.