Yet you confide much more in a boy who is incapable of Occlumency, whose magic is mediocre, and who has a direct connection into the Dark Lord’s mind!
"— mediocre, arrogant as his father, a determined rule-breaker, delighted to find himself famous, attention-seeking and impertinent — " "You see what you expect to see, Severus," said Dumbledore, without raising his eyes from a copy of Transfiguration Today.
There are no more uses of "mediocre" in the book.
Show samples from other sources
the caliber of the students has gone from mediocre to above average
They improved the quality from mediocre to above average