I encountered the word here: 世界で色んな人が食べ物がないから、食べ物を捨ててはならない!と子供の頃から両親 が教えてくれた。
and the 'adjectival' definition in https://jisho.org/search/%E8%89%B2%E3%82%93%E3%81%AA
Edit: Both @Leebo 's and @Aeon Akechi 's answers did answer my question and were rich of useful information. But I accepted the longest answer.