JAVA

spigot despawn entity

entity.remove() // this will mark it for removing

spigot despawn entity

@EventHandler
public void itemVanish2(ItemDespawnEvent e) {
    ItemStack i = e.getEntity().getItemStack();

    if(i.getItemMeta().getLore().contains("FLOATING"))
        event.setCancelled(true); // cancel the event, so item does not despawn
    }
}