Similar Words to Goof:

Blunder
Boob
Bozo
Buffoon
Clown
Cuckoo
Drop The Ball
Fathead
Goofball
Goose
Jackass
Merry Andrew
Sin
Twat
Zany

Examples:

1. Watch me closely. We mustn't goof today.

Definitions of Goof:

1. A man who is a stupid incompetent fool
2. A person who amuses others by ridiculous behavior
3. Commit a faux pas or a fault or make a serious mistake