2. A mistake that one desires to make light of
3. A major screw-up
note: One does not "do" a mainfail, but "hoists" a mainfail. The word originates from the play, "A Christmas Carol" in which actors have been known to yell, "Hoist the mainfail!" when the line is actually "Hoist the mainsail!"
2. Wow. We just made a really stupid mistake. Talk about mainfail hoisting. Now, back to business...
3. You just ran over my dog, the mainfail hoister!