Meaning of sinkage

sink•age

Pronunciation: (sing'kij), [key]
— n.
  1. the act, process, amount, or degree of sinking.
  2. a surface sunk for decorative effect.
    1. the lowering of the first line of body text on a page from its usual position, as at the beginning of a chapter.
    2. the amount of such lowering.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.