Harry potter and the prisoner of azkavan

jerk

sudden, sharp motion -jerk awake

scoff

because he knew Ron would panic and Hermione would scoff.

shrilly

A high, slicing sound — like a whistle or alarm

fitfully

something starting and stopping like flickering candlelight -Harry dozed fitfully, sinking into dreams

petrified

someone frozen in place -and petrified pleading, jerking awake only to dwell again on the sound of his mother’s voice.

dwell on

a mind stuck in a loop

dwell

To stay or remain in one place for an extended time — physically, mentally, or emotionally.

fling

something thrown suddenly and carelessly- Ron finally cracked, flinging a large, slippery crocodile heart at Malfoy, which hit him in the face.