F+ is what you get in school for showing Remarkable Enthusiasm and yet you completed none of the required assignments.
"Kevin, your DVD Series, 'How to do Kick-Ass Stunts' cannot be substituted for 3 Months of Homework Assignments". So, the absolute best grade that I can give you.... is an F+".
Having something very, very shity happen and then have a small good thing happens in relation to it. Or to do a very shity job overall and do one part of it well.
Bob:Damn I just got hit by a car
Steve: That sucks
Bob: But he got out and apologized.
Steve: well that's an F+
Grade used for denoting marginal acceptability.
She gave me dome for almost an hour. I fell asleep twice, but at least she got the job done. I told her she got an F+.