Meaning of light displacement

light' displace'ment

Pronunciation: [key]
— Naut. Naut.
  1. the weight of a ship with all its permanent equipment, excluding the weight of cargo, persons, ballast, dunnage, and fuel, but usually including the weight of permanent ballast and water used to operate steam machinery. Also called
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.