contraction joint: Meaning and Definition of

contrac'tion joint"

Pronunciation: [key]
— Archit., Civ. Engin. Archit.,Civ. Engin.
  1. a joint between two parts of a structure, designed to compensate for the contraction to which either part may be subject.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.