傻乎乎的笑在英语中可以翻译为"dumb laughter"或者"stupid laughter"。这个词描述的是一种感觉傻傻的、不自觉的笑声，通常是由于突然发现某件事很滑稽或者觉得自己很愚蠢而产生的。
下面是一些例句：
"He couldn't stop laughing at his own joke, even though it wasn't funny. It was pke a dumb laughter that just kept coming."（他笑得停不下来，尽管他的笑话并不好笑。这种傻乎乎的笑声一直持续不断。）
"I couldn't help but burst out into dumb laughter when I saw the cat wearing a party hat."（我看到猫戴上了聚会帽子，忍不住爆发出傻乎乎的笑声。）
"She let out a stupid laughter when she reapzed she had left her keys in the fridge."（她发现自己把钥匙放在冰箱里时，突然爆发出傻乎乎的笑声。）
希望这些例句能帮助你理解这个词的含义。