behaving in a way, or describing behaviour, that is slightly bad but is not intended to cause serious harm or damage

She has a mischievous sense of humour. 她很幽默，喜欢搞点恶作剧。

a book about the mischievous antics of his ten-year-old daughter 一本有关他10岁女儿顽皮行为的书

expressing or suggesting mischief

a mischievous grin 不怀好意的狞笑

used to describe behaviour or words that are intended to cause harm or trouble

I think these rumours are mischievous. 我认为这些流言是恶意中伤。