godsend
n. 天赐之物;意外获得的幸运
例句
This new benefit has come as a godsend for low-income families.
新到的救济金是低收入家庭的及时雨。
《牛津词典》
Pharmacists are a godsend when you don't feel sick enough to call the doctor.
有小病痛而又不值得看医生时,药剂师便是最有用的了。
《柯林斯英汉双解大词典》
The opening line read, "Dear Professor Godsend".
而信的开头称呼是“亲爱的、天赐的教授”。