1. 年少粗鲁的;轻狂无礼的
If an older person describes a younger person as sassy, they mean that they are disrespectful in a lively, confident way.

2. 时髦的;漂亮的
Sassy is used to describe things that are smart and stylish.

1. improperly forward or bold

e.g. don't be fresh with me
impertinent of a child to lecture a grownup
an impudent boy given to insulting strangers
Don't get wise with me!

Synonym: freshimpertinentimpudentoverboldsmartsaucywise