sad是和happy最相反的.
伤心
1.(心里痛苦) sad; grieved; heart-broken; broken-hearted: 伤心落泪 shed sad tears; weep in grief; 因受委屈感到伤心 smart under an injustice; 她听到那坏消息伤心的不得了. She took on terribly when she heard the news. 看到自己的孩子被判刑真叫人伤心. It is really heartrending to see his own child be sentenced.
2.[中医] impairment of the heart