(Or "daughter Board", "daughtercard", "daughter card") A printed circuit Board that connects to the motherBoard. The daughterBoard is typically smaller than the motherBoard. A daughterdBoard often adds to or supports the main functions of the motherBoard, unlike an expansion card which provides some new function. For example, a post-release hardware modification might Be released as a daughterBoard for soldering onto the motherBoard. (2004-09-28)