Pronunciation: (hed'rOOm", -room"), [key]
1. Naut.the clear space between two decks.
2. Also called headway. clear vertical space, as between the head and sill of a doorway or between the ceiling and floor of an attic room at a certain point, esp. such height as to allow passage or comfortable occupancy.
3. Audio.See dynamic headroom.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.