Entry: Zuckung (n.)
In context: "His legs were the size his comely arms had been, before Withdrawl. He was haunted by the word Zuckung, a foreign and possibly yiddish word he did not recall ever before hearing."
Definition: From the first translation I could find online:
Zu•ckung f , -, -en (=nervöse Zuckung) twitch
[+von Muskeln auch] spasm
[+von Augenlidern auch] flutter , (stärker, krampfhaft) convulsion
[+von sterbendem Tier] convulsive movement
die letzten Zuckungen (lit, fig) the death throes