Meaning

• A mistake or error.

  "I made a goof in that last calculation."

• A foolish and/or silly person; a goofball.

  "Your little brother is a total goof."

• A child molester.

Meaning

• To make a mistake.

  "It's my fault. I goofed."

• To engage in mischief.

  "We were just goofing by painting the neighbor's cat green."