Meaning of sockdolager

sock•dol•a•ger

Pronunciation: (sok-dol'u-jur), [key]
— n. Older Slang.
  1. something unusually large, heavy, etc.
  2. a decisive reply, argument, etc.
  3. a heavy, finishing blow: His right jab is a real sockdolager.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.