Meaning of dead weight

dead' weight'

Pronunciation: [key]
  1. the heavy, unrelieved weight of anything inert: The dead weight of the bear's body was over 300 pounds.
  2. a heavy or oppressive burden or responsibility.
  3. the weight of a railroad car, truck, etc., as distinct from its load or contents.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.