Something used to describe a situation, usually one that is funny, goofacious, and/or slightly embarrassing. Best used in moderation, as repeated use can make people around you slightly annoyed.
Example 1:
Person A: I accidentally sent a message to the wrong person!
Person B: What a goof moment.
Example 2:
Person A: I bought candy yesterday for me and my sibling, but then I ate it all up on the way home from the store!
Person B: Oh, no!
Person A: Yeah, it was a certified goof moment!
Person B: Please stop.