goof

Etymology

Perhaps from dialectal English goff (“foolish clown”), from earlier goffe, in which case further etymology is uncertain. Perhaps from Middle English goffen (“to speak in a frivolous manner”), possibly from Old English gaf, ġegaf (“base; wanton; lewd”, adj), ġegaf (“buffoonery; scurrility”, noun), gaffetung, golfettung (“buffoonery; mockery”). Compare English dialectal gauffin (“lightheaded; foolish; giddy”), Scots gaff, gawf (“to talk loudly; babble”), Scots gaffaw (“a loud laugh”). Alternatively, perhaps from Middle French goffe (“awkward; stupid”). Compare also Spanish gofo, Italian goffo.

noun

1. (US, informal) A mistake or error.
   I made a goof in that last calculation.
   1. (US, cinematography, informal) An error made during production which finds its way into the final release.
2. (US, Canada, MTE, informal) A foolish and/or silly person; a goofball.
   Your little brother is a total goof.
3. (Canada, prison slang) A child molester.

verb

1. (US) To make a mistake.
   It's my fault. I goofed.
2. (US) To engage in mischief.
   We were just goofing by painting the neighbor's cat green.