What is Sad ?
Sad is (adj) 1. not happy, miserable It’s sad that he can’t come to see us. He’s sad because the holidays have come to an end. What a sad film – everyone was cry- ing. Reading his poems makes me sad. It was sad to leave the house for the last time. He felt sad watching the boat sail away. 2. boring, unfashionable Only sad people col- lect stamps. (NOTE: sadder – saddest)
source: Easier English, Student Dictionary Upper Intermediate Level