Definition Of discard
a person or thing rejected as no longer useful or desirable.
Caught by bottom-trawling, which causes damage to the seabed, and is part of a complex mixed fishery (like cod), and so discards are a problem.
get rid of (someone or something) as no longer useful or desirable.
Hilary bundled up the clothes she had discarded
Example Of discard
A player who cannot follow suit is free to trump the trick or discard an unwanted card.
After discarding eight cards, the starter leads to the first trick.
Before eating it, she proceeded to break off the outer sides, discarding them on the ground at her feet, notwithstanding the fact there was a litter bin nearby.
But essentially if something has no impact whatsoever on your existence and there is no way of proving its existence, then it's discardable in all ethical and philosophical terms.
Earlier this year, the council proposed to hit people who discard gum on the city streets with £50 on-the-spot fines.