Mischievous (adjective)

1. Playfully troublesome or naughty.
2. Having or showing a tendency to cause trouble or harm.

Origin:

From middle english myschief, from old french meschieff, from mes- ("mis-") + chief ("chief, head, mai.n")

Examples:

1. The mischievous children were always up to something.
2. She had a mischievous twinkle in her eye.
3. His mischievous behavior was causing trouble for everyone.
4. The little girl had a mischievous streak and loved to play pranks.
5. The company was criticized for its mischievous advertising campaign that crossed the line.