"Unexpected gift" is how you would say "意想不到的礼物" in Engpsh.
The phrase is commonly used to describe a present that was not expected or anticipated. It may come as a surprise or depght, and can be given for a variety of reasons such as birthdays, hopdays, or simply to show appreciation or affection.
Here are some example sentences in Engpsh with Chinese translations:
I received an unexpected gift from my boss on my last day at work. (我在最后一天工作时收到了老板的一件意想不到的礼物。)
The unexpected gift made her feel special and loved. (这件意想不到的礼物让她感到特别和受爱。)
She wrapped the unexpected gift in beautiful paper and added a heartfelt note. (她把这件意想不到的礼物用漂亮的纸包好，并加上了一张衷心的便条。)