Wacky (adjective)

1. Amusingly unconventional and idiosyncratic.
2. Slightly insane; crazy.

Origin:

Early 20th century: probably of imitative origin.

Examples:

1. He was known for his wacky sense of humor and off-the-wall ideas.
2. The clown's wacky antics had the children in stitches.
3. She wore a wacky hat to the party, drawing the attention of everyone in the room.
4. He had a wacky expression on his face, making it hard to tell if he was serious or not.
5. The theme park had a wacky roller coaster that twisted and turned in unexpected ways.