Sad means feeling unhappy, downcast, or feeling sorrowful. It describes the feeling when something makes you feel low or causes you to shed tears. Full definition
I feel so sad for so many women who are let down, in all countries of the world although some appear to have better records than others. (authenticparenting.info)
And don't you just feel kind of sad for walnuts, they are always my least favorite nut too! (strengthandsunshine.com)
Often, kids don't know what to do when they feel sad so they become aggressive or exhibit attention - seeking behaviors. (verywellfamily.com)