Name ambush describes the situation when an acquaintance you haven't seen for a long time comes across and greets you by name but you cannot remember their name at that moment. You know this is embarrassing, but you can do nothing about it.

Name ambush指你偶然遇到一位很久没见、本来也不太熟的朋友，对方叫着你的名字跟你打招呼，可是你一时间却想不起对方的名字。我们可以戏虐地称之为“姓名伏击”。你知道这样挺尴尬的，可是你也没办法。