Grandma fooler is a gift from someone1 that isn't name-brand or quite what you were expecting2. The name is due3 to the fact4 that usually, grandmas are not up to speed5 on what is popular6. This is usually not good, but sometimes, it turns out ok.
坑奶礼物指的是某人送的非名牌礼物或者不称你心意的礼物。由于老奶奶们一般对时下时尚什么并不了解,所以送她们落伍或过时的东西也没关系,故而得名。这种礼物一般不是特别好的礼物,不过有时也还过得去。
Example:
A: Did7 you get an iPod for Christmas?
B: I got8 an MP3 player9, but it was10 a Grandma fooler.
甲:你圣诞收到iPod了吗?
乙:我收到了一个坑奶礼物MP3。