1. crack a smile 展颜微笑，莞尔一笑
The man was willing to do anything to make his wife crack a smile.
2. laugh a hearty laugh/laugh heartily 放声大笑，开怀大笑
Upon hearing that he had won the lottery, the man laughed heartily.
3. force a smile 强作欢颜
At the funeral, he forced a smile for anyone who offered condolences.
4. saccharine smile 谄笑，谄媚的笑
When he talks to his boss, he puts on a saccharine smile.
5. smile bitterly 苦笑
The student smiled bitterly when his teacher caught him copying his homework.