His face was bloodstained and gaunt, twisted in pain yet rigid with defiance… ’You’ll have to kill me,’ whispered Sirius.
Azkaban had hollowed Bellatrix Lestrange’s face, making it gaunt and skull-like, but it was alive with a feverish, fanatical glow.
’Longbottom?’ repeated Bellatrix, and a truly evil smile lit her gaunt face.
Tall, thin and black-hooded, his terrible snakelike face white and gaunt, his scarlet, slit-pupilled eyes staring… Lord Voldemort had appeared in the middle of the hall, his wand pointing at Harry who stood frozen, quite unable to move.
There are no more uses of "gaunt" in the book.
Show samples from other sources
She looked gaunt from the chemotherapy.
a nightmare population of gaunt men and skeletal boys