Of course, with intensive remedial potions and charms and a bit of luck, we can produce some improvement.
If anybody asks, you are taking remedial Potions.
Til let you know in the usual way when the next one is,’ Harry said over and over again, ’but I can’t do it tonight, I’ve got to go to — er — remedial Potions.’
’You take remedial Potions!’ asked Zacharias Smith superciliously, having cornered Harry in the Entrance Hall after lunch.
Potter is here for a little remedial Potions.
Malfoy mouthed, ’Remedial Potions?’ at Harry behind Snape’s back before following him.
At least he had twenty-four more hours in which to practise; he knew he ought to feel grateful for the narrow escape, though it was hard that it came at the expense of Malfoy telling the whole school that he needed remedial Potions.
There are no more uses of "remedial" in the book.
Show samples from other sources
a remedial reading course
...more than 600,000 of the freshmen who arrived at U.S. colleges this fall—remarkably, 29% of the total—are taking at least one remedial reading, writing or math class.
John Cloud -- Time, 2002 -- http://www.time.com/time/magazine/article/0,9171,1003430,00.html(retrieved 01/20/10)