Ooooops'A
couple pf - what's this codswallop?'
'De-men-tors,' said Harry slowly and
clearly. 'Two of them.'
'And what the ruddy hell are Dementors?'
'They
guard the wizard prison, Azkaban,' said Aunt Petunia.
Two seconds of ringing
silence followed these words before Aunt Petunia clapped her hand over her mouth
as though she had let slip a disgusting swear word.(OotP, UK edition, p.
33)